Google Ads bidding determines how much you pay per click. You choose a bidding strategy: Manual CPC (you set bids), or Smart Bidding (Target CPA, Target ROAS, Maximise Conversions) where Google’s AI sets bids automatically based on conversion signals. Smart Bidding requires 30+ monthly conversions to work well.
Google Ads bidding is the mechanism that controls how much you pay for each click and how your budget is distributed across keywords and auctions. Choosing the right bidding strategy for your campaign’s stage and objectives makes a significant difference to efficiency and results. This guide explains all major bidding strategies for South African advertisers. Related: Google Ads setup guide.
Manual vs Smart Bidding: The Core Choice
All Google Ads bidding strategies fall into two categories: Manual bidding (you set the maximum CPC for each keyword) and Smart Bidding (Google’s machine learning sets bids in real time based on signals). Each has its place depending on where your account is in its maturity cycle.
Manual CPC Bidding
With Manual CPC, you set a maximum CPC bid at the keyword or ad group level. You have complete control over how much you are willing to pay for each keyword. This is the right starting strategy for new accounts with no conversion history — it prevents Google’s algorithms from making uninformed optimisation decisions before they have data to work with.
- Best for: New campaigns, small budgets, accounts with fewer than 30 monthly conversions
- Control level: Maximum — you set every bid manually
- Risk: Requires active monitoring — bids can become uncompetitive or overly expensive without regular adjustment
- Starting bid approach: Use Google Keyword Planner’s CPC estimates as a reference, then adjust based on impression share and position data
Maximise Clicks
Maximise Clicks automatically sets bids to get the most clicks possible within your daily budget. You can set a max CPC cap to prevent paying more than a set amount per click. This is a good bridging strategy for new accounts that want automation without committing to conversion-based optimisation before they have conversion data.
Target CPA (Cost Per Acquisition)
Target CPA tells Google to set bids that achieve a specific target cost per conversion. For example, if you set a target CPA of R500, Google’s algorithm will try to generate conversions at an average of R500 each — bidding higher for searches it predicts will convert and lower for searches it predicts will not.
- Best for: Accounts with 30+ monthly conversions and clear conversion tracking
- Prerequisite: Accurate conversion tracking must be set up and recording real conversions
- Setting the target: Start with a target that reflects your actual recent cost per conversion — do not set an aspirational target the algorithm cannot achieve
- Results: Typically the highest-ROI bidding strategy for mature lead generation accounts
Target ROAS (Return on Ad Spend)
Target ROAS tells Google to bid for conversions that achieve a target return on your ad spend. Used primarily by e-commerce businesses where each conversion has a specific revenue value. If you set a Target ROAS of 500%, Google tries to generate R5 in revenue for every R1 of ad spend.
Maximise Conversions
Maximise Conversions uses Google’s algorithm to get the maximum number of conversions within your daily budget, without a specific CPA target. Useful when you have sufficient conversion data but are not yet confident in setting a precise CPA target. It is often a good transitional strategy between Maximise Clicks and Target CPA.
Google’s bidding strategies documentation provides the full technical explanation of each strategy and the data requirements for each Smart Bidding approach.
Frequently Asked Questions
Should I start with Manual CPC or Smart Bidding?
Start with Manual CPC or Maximise Clicks for new accounts. Smart Bidding strategies like Target CPA require at least 30 monthly conversions to optimise effectively. Switching to Smart Bidding before you have this data typically produces poor results because the algorithm has insufficient signal to make intelligent decisions.
What is Enhanced CPC (ECPC)?
Enhanced CPC is a hybrid approach — you set manual bids, but Google automatically adjusts them up or down by up to 30% based on real-time conversion signals. It is a stepping stone between full Manual CPC and full Smart Bidding. Google is gradually phasing it out in favour of the full Smart Bidding strategies.
How do I know if my bids are too low?
Check your Impression Share metrics. ‘Impression Share Lost Due to Rank’ tells you what percentage of eligible auctions you missed because your Ad Rank was too low (either your bid was too low or your Quality Score was too low). If this metric is above 20-30%, your bids may need increasing — or your Quality Score needs improving, which achieves the same result more efficiently.
Can I set different bids for mobile vs desktop?
Yes — bid adjustments allow you to modify your base bids by device type, location, audience, time of day, and several other signals. For example, if your campaigns convert at a higher rate on mobile, you can set a +20% mobile bid adjustment to win more mobile auctions competitively. Bid adjustments work on top of your base bid (manual bidding) or as signals for Smart Bidding.
What is the difference between Target CPA and Target ROAS?
Target CPA is used when you optimise for number of conversions at a consistent cost (typical for lead generation). Target ROAS is used when conversions have different revenue values and you want to optimise for revenue return (typical for e-commerce). For a South African accountant generating enquiries, Target CPA is appropriate. For a South African e-commerce store selling products at different prices, Target ROAS is more suitable.