13 min read · Google Ads · Last updated July 2026
Quick answer: Choose your bidding strategy based on how much conversion data you have and what your goal is. Under 30 conversions/month: Maximize Conversions. 30-100 conversions/month: Target CPA. Over 100 conversions/month with known revenue: Target ROAS. Manual CPC is valid for very low-volume, high-CPC scenarios where you want maximum control.
Introduction
Choosing the wrong bidding strategy doesn’t just affect performance — it can drain an entire budget in days. A new account switched to Target ROAS with only 8 conversions in its history. Google had no data to work with. It spent $4,000 in 10 days on low-converting traffic, chasing a ROAS target it couldn’t achieve.
Bidding strategy choice is not about which sounds best. It’s about matching the strategy to your data, goals, and account maturity.
What you’ll learn:
– What each bidding strategy actually does under the hood
– The exact data thresholds each strategy needs to work
– How to transition safely between strategies
– Which strategy to use for your specific situation
Table of Contents
- How Google’s Bidding System Works
- Manual CPC
- Enhanced CPC (eCPC)
- Maximize Clicks
- Maximize Conversions
- Target CPA
- Target ROAS
- Maximize Conversion Value
- Bidding Strategy Decision Matrix
- FAQ
How Google’s Bidding System Works
Every time someone performs a Google search that matches your keyword, an auction runs. Your bid is one input — but what Google actually uses is your Ad Rank, which factors in bid, Quality Score, auction-time signals, and expected impact of extensions.
Smart bidding strategies (Target CPA, Target ROAS, Maximize Conversions, Maximize Conversion Value) adjust your bid in real-time for every single auction using machine learning. They consider signals like:
- Time of day and day of week
- Device type (mobile vs desktop)
- Location (city-level precision)
- Browser and operating system
- Search query specifics
- User’s search history
- Audience membership
- Predicted conversion probability
Manual strategies can only apply blanket adjustments you manually set. Smart bidding adjusts for all these signals simultaneously — which is why it outperforms manual bidding once you have sufficient data.
Manual CPC
Manual CPC gives you complete control. You set the maximum bid for each keyword individually. Google will never spend more than your specified bid per click.
When Manual CPC makes sense:
– Brand new campaigns with zero conversion history
– Very low-volume, high-CPC industries where every click matters ($50+ CPC)
– Situations where you want to test keyword performance before committing to smart bidding
– Accounts where conversion tracking cannot be implemented
Limitations: You’re setting one bid for all users, all times, all devices. A search at 9pm on mobile from a rural area gets the same bid as a search at 9am on desktop from central Sydney — even though they convert at very different rates. Manual CPC leaves performance on the table.
Bid management with Manual CPC:
Set bids at 80-120% of the first-page bid estimate for each keyword. Review weekly. Increase bids on high-CTR, converting keywords. Decrease or pause keywords with high spend and no conversions.
Enhanced CPC (eCPC)
Enhanced CPC is Manual CPC with a modifier. Google adjusts your manual bids up (by any amount) when it predicts a click is more likely to convert, and down (by up to 100%) when conversion is less likely.
eCPC is the bridge between full manual control and smart bidding. As of 2026, Google has been gradually deprecating eCPC for Search campaigns in favour of fully automated strategies. It’s still available but being phased out.
Best use case: Accounts where you want human oversight on base bids but want some algorithmic lift on individual auctions.
Maximize Clicks
Maximize Clicks tells Google to get as many clicks as possible within your daily budget. It doesn’t care about conversion rate, conversion value, or cost per conversion.
When to use Maximize Clicks:
– Top-of-funnel awareness campaigns where traffic volume matters
– New campaigns before you have conversion data
– Display campaigns for reach (combined with frequency caps)
The risk: Google will find the cheapest clicks possible — which often means lower-quality traffic. A Maximize Clicks campaign will quickly find keywords where people click but don’t convert (low-intent, window shoppers).
Set a maximum CPC bid cap to prevent Maximize Clicks from bidding wildly on expensive terms. Without a cap, it can exhaust your budget on a handful of high-CPC clicks.
Maximize Conversions
Maximize Conversions tells Google to generate as many conversions as possible within your daily budget. No CPA target — just spend the full budget and get as many conversions as it can.
This is the recommended starting strategy for new campaigns that have conversion tracking set up.
Data requirement: Active conversion tracking. No minimum historical conversions required — but performance improves dramatically as data accumulates.
Learning period: 6-8 weeks or 50 conversions, whichever comes first. During this period, don’t make major changes (bid strategy, keywords, budgets) or the learning resets.
The risk: Maximize Conversions has no CPA guardrail. If your budget is $100/day and conversions cost $200 each, it will still spend the full $100. Always monitor CPA during the learning period.
Transition to Target CPA once you have 30+ conversions in a rolling 30-day window and have identified what your actual average CPA is.
Target CPA
Target CPA (tCPA) tells Google to generate as many conversions as possible at or below your specified cost-per-acquisition. You set the target; Google adjusts bids for every auction to hit it.
This is the most commonly used smart bidding strategy for lead generation and service businesses.
Setting your tCPA target:
Don’t set your ideal CPA from day one. Set it at 20-30% above your current actual average CPA, then lower it gradually (10-15% at a time, every 2-3 weeks) as the campaign accumulates data.
If you set tCPA too low initially, Google won’t find enough qualifying auctions to spend your budget, and impressions will drop dramatically.
Data requirement: 30+ conversions in the last 30 days. Below this threshold, use Maximize Conversions without a target.
Target ROAS
Target ROAS (tROAS) optimises for conversion value rather than conversion volume. You tell Google the return on ad spend you want, and it adjusts bids to hit that revenue target.
Example: Set tROAS at 400% → for every $1 spent, aim to generate $4 in revenue.
Data requirement: 50+ conversions with values tracked in the last 30 days. tROAS is hungry for data — with insufficient history, Google will either over-bid (burning budget) or under-bid (missing traffic).
When to use tROAS:
– Ecommerce accounts with tracked purchase values
– Lead gen accounts with consistent average deal sizes (offline conversion import)
– When maximising revenue is more important than minimising CPA
Setting your tROAS target:
Calculate your current actual ROAS first. Set the initial tROAS target 10-20% below your actual ROAS to give Google flexibility. Gradually increase the target.
Maximize Conversion Value
Similar to Maximize Conversions, but optimises for total conversion value (revenue) rather than conversion count. Without a ROAS target, it will spend your full budget to maximise total revenue — useful when different conversions have different values.
This is the predecessor step before moving to Target ROAS, analogous to how Maximize Conversions precedes Target CPA.
Bidding Strategy Decision Matrix
FAQ
Q: Can I switch bidding strategies mid-campaign?
A: Yes, but each switch triggers a new learning period (typically 1-2 weeks). Avoid switching more than once per month. Make the switch during a stable period, not during peak season.
Q: What happens during the “learning period”?
A: Google’s algorithm is testing and calibrating. Performance is often worse than average during learning. Don’t panic and switch back — let it complete. Expect normalisation after 2-3 weeks.
Q: My Target CPA campaign stopped getting impressions after I lowered my CPA target. Why?
A: The target is too low for Google to find qualifying auctions. Google predicts most available clicks will cost more than your target, so it doesn’t bid. Raise the target 20-30% until impressions return, then lower gradually.
Q: Should I use portfolio bid strategies?
A: Portfolio strategies let you apply one smart bidding strategy across multiple campaigns. Useful when individual campaigns don’t have enough conversion data on their own but the combined portfolio does. Good for small budgets spread across multiple campaigns.
Q: Does bidding strategy affect Quality Score?
A: No. Quality Score is determined by expected CTR, ad relevance, and landing page experience — not bidding. However, smart bidding strategies may show your ads to more relevant audiences, which can indirectly improve CTR over time.
Q: Target CPA says it hit my target but CPA in my CRM is much higher. Why?
A: Google measures CPA based on its conversion window (default 30 days last click). Your CRM might count only leads that converted to sales, or use different attribution. Always reconcile Google’s CPA with your actual business CPA.
Conclusion
Bidding strategy is not a set-and-forget decision. It evolves with your account. Start conservative, build data, graduate to smarter strategies as you earn the data to support them.
The biggest mistake is applying Target CPA too early, setting it too aggressively, then abandoning Google Ads because “smart bidding doesn’t work.” Smart bidding works — when you give it the data and time it needs.
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Written by the Ignited Nepal paid acquisition team. ignitednepal.com