Bid strategy
The rule you give an ad platform for how hard to bid in each auction: chase volume, hold a cost target, or cap the maximum price.
See it
What it is
Most ad impressions are sold in a real-time auction (reserved buys and direct-sold inventory are the exception, and they are priced by a contract, not a bid), and a bid strategy is the standing instruction you give the platform about how hard to bid on your behalf. The usual menu: spend it all for maximum volume (Meta 'Highest volume', Google 'Maximize conversions'), hold an average cost (cost per result goal, Target CPA), hold a revenue ratio (ROAS goal, Target ROAS), or never pay more than X (bid cap, manual CPC).
Default to volume bidding while you are small and learning, then move to a cost or ROAS target once you have stable conversion data and an actual number you must hit. Caps are for when a click above a certain price genuinely cannot pay back, not for when you feel nervous.
Gotcha: a tight cap does not get you cheap results, it gets you no results. The platform simply loses auctions, delivery stalls, and you conclude the channel does not work. Second gotcha: changing bid strategy (or budget, by a lot) restarts the learning phase. How many conversions it takes to exit varies by platform, objective, and bid strategy, so trust the number the ad manager shows you for that specific setup rather than a figure someone repeated on a podcast. Change one thing, then leave it alone for a few days.
Ask AI for it
Recommend a bid strategy for this campaign and write out the exact settings. Context: [platform], [monthly budget], [conversion event], [current cost per result], [target cost per result or target ROAS], [how many conversions per week the account gets]. Give me: the strategy to pick and why, the starting target or cap number with the arithmetic behind it, what the learning phase will look like for the first 7 days, the two metrics that tell me it is working, and the specific failure signal (stalled delivery, rising CPM, no spend) that means I set the target too aggressively.