Google Ads Bidding Strategy: How to Choose Between tCPA, tROAS, Maximize Conversions, and Manual
Most bidding problems are really data problems. This page is the decision process John Williams uses to choose
and manage Google Ads bid strategies, based on official documentation and what he has seen across $350M+ in
managed spend.
Smart Bidding is Google's name for four strategies: Maximize conversions, Maximize conversion value, Target
CPA, and Target ROAS. All four bid at auction time using conversion data.
The strategy matters less than what it optimizes toward. If junk actions are set as Primary conversions,
every strategy will optimize for junk.
John's default path: get tracking clean, run Maximize conversions without a target to learn your real CPA,
then add a target you can actually hit.
Use portfolio strategies to pool data across thin campaigns. Manual CPC still makes sense in a few specific
cases.
Since June 2026 the labels read simply "Target CPA" and "Target ROAS." A separate August 17, 2026 update
changed how target-based bidding behaves when budgets are tight.
Who this is for
You need this if any of these sound familiar: "Smart Bidding spends but doesn't convert.""We set a Target CPA and volume fell off a cliff.""Our campaigns say 'Limited by bid strategy.'""Leadership wants ROAS and we're optimizing to form fills." Bid strategy work fits in-house teams who
want a second opinion before a big change, and agencies who want a specialist review. It is also part of every
managed Google Ads engagement.
The strategies, in plain terms
Google defines Smart Bidding as strategies that "use Google AI to optimize for conversions or conversion value
in every auction," and names four of them (About Smart Bidding). Everything else is either automated but not conversion-based (Maximize clicks, Target impression share) or
manual.
Strategy
What it does
John uses it when
Maximize conversions
Spends the budget to get as many conversions as possible (Google Ads Help).
You need a baseline. Running it without a target for a few weeks tells you what CPA the market will
actually give you.
Target CPA
Aims for an average cost per conversion you set (Google Ads Help).
Every conversion is worth roughly the same (one lead type, one product) and you know your achievable CPA.
Maximize conversion value
Spends the budget to maximize total conversion value.
Values differ meaningfully between conversions and you'd rather grow volume than hold a strict efficiency
target.
Target ROAS
Aims for a return on ad spend you set.
Values are accurate, ideally margin or profit rather than gross revenue, and there's enough volume. Google
recommends evaluating over windows with at least 50 conversions for Target ROAS.
Maximize clicks
Automated, not conversion-based.
Brand-new campaigns with no conversion history, for a short time only.
Manual CPC
You set the bids.
See "When manual still wins" below.
Two changes in 2026 are worth knowing. First, starting in June 2026 Google relabeled "Maximize conversions with
a Target CPA" as just "Target CPA," and the ROAS equivalent as "Target ROAS," with the bidding behavior
unchanged (About Smart Bidding). Second, Google says that starting August 17, 2026 it is updating its bidding systems for
budget-limited campaigns on Target CPA or Target ROAS, warns of temporary fluctuations, and added a Bid
Target Adjustment Tool on July 6, 2026 (About Target CPA bidding). If your target-based campaigns moved in late August, that's the first thing to check. The section on the
August change below covers what to do about it.
What's included in a bid strategy review
Conversion audit for bidding. Every Primary action, its counting setting, its value, and
whether it belongs in the goal the strategy optimizes toward.
Data volume map. Conversions and conversion value per campaign and per portfolio over the
last 30 and 90 days, so each recommendation rests on what the data can support.
A written recommendation for every campaign: the strategy, the target if any, the reason, and
what would change the decision.
Target review against the August 2026 change. Actual CPA or ROAS against the stated target
for every budget-limited campaign, with a keep, tighten, or add-budget call for each.
Test plan. Which changes go out as Google Ads experiments, how long each runs, and the metric
that decides it.
Guardrails: a data exclusion runbook for tracking outages, seasonality adjustments for short
promotions, and alerts for sudden CPA or ROAS swings.
A 30-day follow-up comparing results with the forecast in the recommendation.
How John decides: the actual sequence
Audit what "a conversion" means
Only Primary conversion actions in goals used for bidding feed the "Conversions" column that the strategy
optimizes against (primary vs. secondary actions). John's Monday-morning test from his
conversion tracking article: open Goals > Conversions > Summary, check that every Primary action is a real business outcome, and
demote everything else.
Count the data per campaign
Google recommends evaluating Smart Bidding over periods with at least 30 conversions, or 50 for Target ROAS
(About Smart Bidding). John's working rule is the same floor of 30 a month, ideally 50 or more. A campaign that falls short
either gets merged with others, joins a portfolio strategy, or optimizes to a higher-volume conversion
that's still meaningful.
Decide between counting and valuing
If a $40 lead and a $4,000 lead count the same, a CPA strategy can't tell them apart. When values really
differ and you can pass them (through order value, lead scoring, or offline imports with value), move toward
value-based bidding. When they don't, stay with CPA. A value strategy built on made-up values is worse than
a CPA strategy built on honest counts.
Start without a target, then add one
A target set too aggressively makes Smart Bidding stop bidding rather than miss it. You end up with zero
conversions instead of expensive ones. John starts with Maximize conversions without a target to find the
real achievable CPA, then sets a target near that number. Google's own recommended Target CPA is based on
the last 30 days' average CPA, adjusted for conversion delay (About Target CPA bidding).
Change slowly and test properly
Google describes a standard 7–14 day learning phase and warns that frequent changes to budgets, targets, or
goals reset it (Google Ads Help). We move targets in measured steps, use the "Save as experiment" option for bigger changes, and judge
results against the strategy's average target CPA (the target it actually pursued) rather than the
number in the settings.
Protect the model from bad days
If a tag breaks, we apply a data exclusion for the affected click dates. Google advises excluding at least
90% of the impacted clicks, accounting for conversion delay, and not removing the exclusion afterward (About data exclusions). For short, known spikes such as a 1–7 day sale, a
seasonality adjustment
tells Smart Bidding ahead of time.
Bidding mistakes John fixes most
Reading "Lost IS (budget)" on Maximize conversions. Google says that column is incompatible
with Maximize conversions, which is meant to spend the full budget. Use the budget simulator instead (About Maximize conversions).
Leftover bid adjustments. On Maximize conversions, existing bid adjustments are ignored
except a -100% device adjustment. On Target CPA, device adjustments change the CPA target, not the bid. Teams
keep tuning adjustments that do nothing.
Ad group targets everywhere. Google says setting separate ad group targets "isn't recommended
as it can restrict Smart Bidding." We use them only where the economics really differ.
Backfilling after an outage. Google advises against backfilling conversion data, because it
can directly affect Search and Shopping bidding. Exclude first. Backfill for reporting only after at least
five days (data exclusions).
Revenue values on low-margin products. Target ROAS on gross revenue happily sells your
lowest-margin products. One anonymized ecommerce audit on our
case studies page moved to profit-based conversion values for exactly this
reason.
The August 17, 2026 change to target-based bidding
This is the bidding change most accounts haven't fully absorbed. Before August 17, 2026, a Target CPA or Target
ROAS campaign that was limited by budget could beat its target by a wide margin, and performance could swing
when budgets were adjusted. Google's update makes those campaigns "perform more consistently toward your bid
target, including when you make budget adjustments" (Changes to target based bid strategies).
Google's own example: a campaign with a $10 Target CPA that had been delivering a $5 actual CPA "now delivers
more closely to a $10 USD actual CPA." To keep the old efficiency, you lower the target to $5. Google states it
won't adjust targets or budgets for you. The change covers Search, Shopping, Performance Max, and Demand Gen.
App campaigns and video reach and view campaigns keep the previous behavior, and Hotel and Display already
worked this way. For Performance Max and Demand Gen, Google also warns that traffic may shift between channels.
How John works through it:
List every budget-limited campaign on a target, with its stated target and its actual 30-day
CPA or ROAS.
Decide what the target is for. If the stated target is the real break-even number, keeping it
buys more volume at a higher cost per conversion, which may be exactly right. If the business got used to the
better actual number, tighten the target to match it.
Consider budget instead of target. Google notes you can raise the budget to capture more
volume at your stated target. That's often the cleaner lever when the target is correct.
Use the Bid Target Adjustment Tool, available since July 6, 2026, to review suggested
targets, but check each against your margins before applying it.
Annotate the date. Any year-over-year comparison that crosses August 17, 2026 needs a note,
or someone will blame the wrong change.
Portfolio bid strategies: when to pool
A portfolio strategy groups several campaigns, ad groups, and keywords under one shared goal. It can use any of
the four Smart Bidding strategies, plus Maximize clicks or Target impression share. It isn't available for
Performance Max (Portfolio bid strategy).
John uses portfolios for three things:
Pooling thin data. Five regional campaigns at 8 conversions a month each, under one Target
CPA, give the algorithm 40 conversions to learn from.
Bid limits on Search. Max and min CPC limits for Target CPA only exist in portfolio
strategies, and only apply in Search Network auctions (About Target CPA bidding). Google doesn't recommend them. John uses a max CPC limit only as a guardrail on volatile, expensive terms.
Keeping budgets separate. Campaigns can share a bidding goal while each keeps its own budget.
That's useful when finance needs spend reported by line of business.
When manual CPC still wins
Manual isn't a moral stance. It's the right tool in a few narrow situations:
No trustworthy conversion signal yet, and you can't fix that this month.
Very low volume where even a portfolio can't get near 30 conversions a month.
Hard cost caps on specific terms (some regulated or ultra-expensive categories) where a
single runaway click is a real problem.
Short tests where you need to isolate an ad or landing page change from bidding swings.
Brand campaigns usually go the other way. John's practitioner note in his
Smart Bidding article: for brand campaigns with consistent conversion data, Smart Bidding is almost always the right call. For
non-brand campaigns with fewer than 30 conversions a month, Maximize clicks can build volume first.
Pricing and engagement
Bid strategy work comes two ways. It's part of every
managed Google Ads engagement, which is a flat
monthly fee quoted after the free 30-day audit, or it can be a standalone review with a written recommendation
for each campaign. Either way, per the pricing page, nothing is billed as a percentage
of spend and there are no long contracts.
Platforms we work in
Bid strategy decisions depend on clean conversion data and honest reporting. These are the official tools
involved.
None is best in general. Target CPA fits when every conversion is worth about the same. Target ROAS or
Maximize conversion value fits when values differ and you can measure them accurately. Maximize conversions
without a target is the right way to establish a baseline. Manual CPC fits only when there's no reliable
conversion signal or volume is very low.
How many conversions do I need for Smart Bidding?
Google lets you start with no history, but recommends evaluating performance over periods with at least 30
conversions, or 50 for Target ROAS. John treats 30 per month per campaign or portfolio as the working floor,
with 50+ preferred.
Why did my conversions drop after I set a Target CPA?
Usually the target is lower than the market will give you, so the system bids less or skips auctions. Go back
to Maximize conversions or raise the target close to your actual 30-day CPA, then lower it in steps.
What happened to Enhanced CPC?
Google retired Enhanced CPC for Search and Display the week of March 31, 2025. Campaigns that weren't migrated
now effectively run on Manual CPC. Check your campaigns, because many accounts still have them.
Did Google change Target CPA in 2026?
Twice. In June 2026 the label "Maximize conversions with a Target CPA" became "Target CPA," with the same
behavior. Then from August 17, 2026, budget-limited Target CPA and Target ROAS campaigns deliver closer to the
stated target instead of beating it, so a campaign that was outperforming may need its target lowered. Google
added a Bid Target Adjustment Tool on July 6, 2026.
Should I use a portfolio bid strategy?
Use one when several campaigns share a goal but none has enough conversions alone, or when you need Search bid
limits, which only exist in portfolio Target CPA strategies. Portfolios aren't available for Performance Max.
Get a second opinion on your bidding
Send the campaign names, current strategies, and what changed when performance moved. John will reply with a
written read on what to change first.
John, Kristy, or Sandeep will reply.One of the three of us will respond personally within 1 business day. No SDR queue.
Message received.
One of us will reply directly within one business day. While you wait, run a free
Buddy audit on your account.
Top 25 references
The primary sources, standards, research, and tools we rely on for this work. Every link was checked on
2026-10-11. We aren't affiliated with these publishers unless noted.
Official documentation
About Smart Bidding— Google Ads Help Google's definition of Smart Bidding, the 30-conversion (50 for tROAS) evaluation guidance, and the
June 2026 labels.
About Target CPA bidding— Google Ads Help How the recommended target is set, portfolio-only bid limits, ad group targets, and average target
CPA.
About Target ROAS bidding— Google Ads Help How Target ROAS uses conversion values and what data it needs to work.
About Maximize conversions bidding— Google Ads Help Why Lost IS (budget) doesn't apply and why bid adjustments are ignored except a -100% device
adjustment.
Portfolio bid strategy: Definition— Google Ads Help Which strategies can be portfolios and the note that portfolios aren't available for Performance
Max.
Changes to target based bid strategies— Google Ads Help The August 17, 2026 change: budget-limited tCPA and tROAS campaigns now deliver closer to the stated
target.
Autobidding with Constraints— Google Research (Aggarwal, Badanidiyuru & Mehta) The theory of bidding to maximize value under a CPA or ROAS constraint, the model behind target-based
bidding.
Measuring Ad Effectiveness Using Geo Experiments— Google Research (Vaver & Koehler) The method behind matched-market tests, used to measure incremental conversions when platform-reported
numbers can't be trusted.
Industry reports & benchmarks
Google Ads Benchmarks for Your Industry— WordStream by LocaliQ Annually refreshed CTR, CPC, conversion rate, and cost-per-lead benchmarks by industry, useful as a sanity
check rather than a target.
Search Engine Market Share Worldwide— Statcounter Global Stats Context for how much auction volume sits on Google versus other engines when deciding where to scale.
Leading tools
Meridian— Google for Developers Google's open-source marketing mix model, useful for checking whether bidding targets match true
incrementality.
Google Ads Editor— Google Google's free desktop app for offline bulk edits, used for large restructures and reviewing changes
before they post.
Google Ads Scripts: product overview— Google for Developers JavaScript automation inside Google Ads for alerts, budget pacing checks, and custom reports.
Optmyzr— Optmyzr A widely used PPC management platform for Google and Microsoft Ads rule-based automation, audits, and
alerts.
Expert guides
What is PPC – Pay-Per-Click marketing?— Search Engine Land Search Engine Land's maintained primer on how paid search auctions, platforms, and campaign planning
fit together.
A Complete PPC Marketing Guide— Search Engine Journal A multi-chapter guide from Search Engine Journal covering account structure, keyword research, bidding, and
reporting.
Communities & courses
r/PPC— Reddit The largest practitioner forum for paid search, useful for spotting platform bugs and rollout issues before
they're documented.
Skillshop: Google Ads certifications— Google Google's free training and certification portal for Search, Shopping, measurement, and AI-powered
campaigns.
AI disclosure: This page was drafted with AI assistance and edited by a human. Platform rules and
limits are cited to official documentation as checked on 2026-10-11; Google, Microsoft, and Meta change these
often, so confirm against the linked source before acting. Brand names mentioned in John's background are past
engagements listed on the about page; no current endorsement is implied.
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