AdMob bidding is now the default for most setups in 2026, but a non-trivial number of indie studios still run classic waterfalls — either because they started before bidding was solid, or because they have a custom direct-deal layer that doesn't fit neatly into a bidding-only stack. This article is for those studios.
Should you migrate to bidding at all?
Three signals say yes:
- You spend more than 2 hours a week tuning floors and re-ordering lines.
- Your top three networks are all bidding-capable (most are, in 2026).
- Your waterfall has more than 30 lines.
Three signals say wait:
- You have a substantial direct-deal layer with hard floors and date windows.
- Your waterfall has 6–10 lines and is stable — bidding rarely beats a tight, well-tuned waterfall at that scale.
- You operate primarily in markets where bidding inventory is thin (some Tier 3 countries, some genres).
The four floor-tuning rules that actually move revenue
Most indie waterfalls leak revenue not because the structure is wrong but because the floors are slightly off in four specific ways:
Rule 1: Floor by country, not just by ad unit
A single floor across all geos is leaving 10–25% on the table. JP, US, KR, DE, AU, UK all clear at different rates. The minimum useful split is three buckets — Tier 1 (US, JP, UK, AU, DE, CA), Tier 2 (most of Western Europe, ROW high-value), Tier 3 (the rest). AdMob lets you set this at the ad unit level.
Rule 2: Floor by format separately
Rewarded video clears at 3–10x banner. The same studio that floors banner at $0.30 and rewarded at $8 globally is probably either over-flooring banner in Tier 3 or under-flooring rewarded in Tier 1. Don't copy floors across formats.
Rule 3: Re-tune every 30 days
Market eCPM drifts. A floor tuned in November will be 5–20% off by February. Put a recurring calendar item for "floor review" at the same cadence as your QA review. If the answer is "no change", you spent 5 minutes — cheap insurance.
Rule 4: Use the 80th percentile, not the average
Floors should be set near the 80th-percentile clearing price for the ad unit, not the average. The point of a floor is to refuse bad fills; setting it at the average causes you to refuse roughly half of all impressions, which crashes fill and blended eCPM. AdMob's "optimized" floor recommendation usually targets the right zone — sanity check it but trust it as a starting point.
Network-order rules of thumb
For a classic waterfall, the order matters less than people think — modern AdMob will re-sort by realized eCPM within a few days anyway. What matters is which networks you actually include. Reasonable defaults:
- AdMob (always)
- Meta Audience Network (bidder if available)
- Unity Ads (especially in gaming)
- AppLovin (yes, even if you're running AdMob — its programmatic demand is additive)
- One regional network if you have substantial JP/KR/CN presence (e.g., UNICORN, Maio, FAN for JP)
Don't over-stack. Past 7–8 networks the marginal revenue from network #9 is below the operational cost of monitoring it.
When to actually go bidding
The honest answer is "when you stop spending time managing the waterfall and start wanting to spend time on something else." Bidding shifts the optimization problem from "ordering and pricing" to "monitoring eCPM and intervening when something looks off." That's a better problem to have, and tools like Mediation One are specifically designed for it.