Bid strategies & cost controls
Yesterday: how much you spend and who allocates it. Today: how aggressively the system competes for each result, and whether you cap the price. The dial between "spend it all" and "protect my margin."
The bid strategy answers one question - "what's our goal when bidding in each auction?" Three families, on a spectrum from max-volume to max-control.
1Highest Volume (Lowest Cost) — the default
"Get me as many results as possible for my budget, whatever each costs." Meta spends the full budget and bids automatically to maximize result count. No price cap.
- Use when: starting out, prospecting, or you'll judge the average cost after.
- Trade-off: you don't control cost per result - on a competitive day CPA can rise. But it almost always spends fully and exits learning fastest.
2Cost Per Result Goal (Cost Cap) — the balance
"Keep my average cost per result around €X while getting as much volume as possible." You give a target; Meta tries to hold the average there.
- Use when: you know your acceptable CPA and want volume without the average drifting above it.
- Trade-off: set it too low and Meta can't find enough cheap results, so delivery throttles. It's a target average, not a hard per-result ceiling.
3ROAS Goal & Bid Cap — the tight control
- Highest value the volume-family sibling for e-com: spends the full budget to maximize total purchase VALUE instead of result count — no target, no cap.
- ROAS goal "aim for this average return on ad spend" (value optimization; needs reliable purchase-value data). Like Cost Cap, it's a target average the system works toward — not a guaranteed floor. For revenue-focused e-com.
- Bid cap "never bid more than €X in any auction." Most manual, most controlling. Powerful for experienced buyers protecting margin; dangerous for beginners - too low and you win almost nothing.
The tighter you constrain Meta, the less it can spend. Every cap is a brake. A cap set too aggressively doesn't deliver cheap results - it strangles delivery, keeps you in learning, and starves volume. Loosen it and volume opens; tighten it and volume chokes. Most beginners set caps far too tight, see almost no spend, and panic. Why? Remember Day 2 — every impression is an auction and your bid is one input into total value. A cap below the going clearing price doesn't make results cheaper; you simply lose auction after auction, and the budget sits unspent.
Recommended progression: start on Highest Volume to learn what a result actually costs you. Once you have a stable, true CPA, graduate to a Cost Cap slightly above that number to defend it while scaling. Only reach for bid caps when you genuinely know the auction and your margins.
Your last 30 days show a stable CPA of €25. First cost cap: €28-30 (10-20% above the real number) — defends margin while leaving the auction room to breathe. The €15 you wish you paid? That's the cap that kills delivery.
Highest Volume = "here's €100 for the day — get me as many rides as possible, whatever each fare costs." Cost Cap = "keep my average fare across trips around €20." Bid Cap = "never let any single trip exceed €20" - and if no driver accepts, you don't move at all. The tighter the rule, the more often you're left on the curb.
At the ad-set level — or at the campaign level if you switched on Advantage+ campaign budget yesterday (Day 6) — in "Bid strategy" / "Cost per result goal":
After setting any cap, watch daily spend next to your CPA: if spend collapses, the cap is too tight — loosen it before you touch anything else.
(1) Setting a cap at their dream CPA, not a realistic one - delivery dies. (2) Treating Cost Cap as a hard per-result ceiling - it's a target average. (3) Changing bid strategy frequently - a significant edit that resets learning. (4) Reaching for bid caps as a beginner. The honest default for almost everyone is Highest Volume until the data says otherwise.
Find every bid control with your own hands, in a draft ad set that never goes live.
Recap - 30 seconds
- Bid strategy = the system's goal in each auction, from max-volume to max-control.
- Highest Volume (default): max results, no cap, spends fully, exits learning fastest.
- Cost Cap: hold average CPA near a target while maximizing volume.
- ROAS goal / Bid cap: tightest control, for experienced buyers protecting margin.
- Golden rule: every cap is a brake - too tight chokes spend and traps you in learning.