Key takeaways
A waterfall calls demand partners one after another in a priority order set by price floors, while bidding lets partners price the same impression at the same moment so the highest bid wins. Many apps run both, with bidding partners competing live and waterfall lines filling what bidding leaves. TapMind MetaMediation adds demand to the mediation you already run and does not replace it.Most mediation stacks were built as a waterfall: call partner one, then partner two, then whoever is left. Bidding arrived later and asked for the same impression at the same time. The useful question is not which model replaces the other. It is how both can sit in one setup without the publisher giving up the control they already have.
Why both models belong in one setup
A waterfall is predictable. You decide the order, you can see who was called, and a partner who has earned a place stays there until the numbers say otherwise. Bidding is less polite. Everyone who can answer does, and the highest usable price wins that request.
Publishers who already have a working waterfall rarely want to throw it away to “move to bidding.” They want the incremental demand. That is the job of an added path: keep the mediation you run, and let another path compete beside it.
The existing mediation stays in place. The new path is there to be measured, not to take the stack over on day one.
What stays with the publisher
Priority, traffic share and the right to pause a partner do not move. If a bidder is noisy, slow or out of policy, it can be reduced or removed without touching the partners already in the waterfall. If a waterfall partner starts to clear at a better price than the bid path, it keeps its place.
- No setup fee and no requirement to migrate the current mediation.
- One connection can carry marketplace demand and partners you already know.
- Proven partners can later move into your own mediation if you want them there.
How the request actually travels
On a custom-adapter path, TapMind is registered as one more demand line inside the mediation you already run. The mediation still decides when that line is called. On an orchestration path, a no-fill from the current setup can hand the request to a separate route, which then runs its own configured demand.
Both are valid. They answer different constraints: the adapter changes less of the app, the orchestration path can try again when the first route returns nothing.
When bidding wins on price
Bidding earns the impression when a partner returns a price the waterfall would not have reached in its current order. That only counts if the response arrives in time and the creative can actually render. A high number that times out is not revenue.
When the waterfall still earns its place
Some partners are not bidders. They are called in an order you set, they fill a format the bid path does not, or they pay on a commercial term you have already agreed. Forcing them into an auction they cannot join just creates no-fill. Leave them in the sequence, and let bidding compete where it can.
What publishers should measure
Look past the single highest CPM. The useful set is realized revenue, fill, response time and how often a “win” actually rendered. A path that looks strong in the bid log and weak in the payout report is not the path to expand.
| Signal | What it tells you |
|---|---|
| CPM | The price offered or cleared, not the price you keep. |
| Fill rate | How often a called opportunity returns an ad. |
| Response time | Whether the bid is usable before the impression expires. |
| Rendered revenue | What survived the player, the policy checks and the payout. |
A practical way to start
Add the extra path next to the mediation you trust. Cap its traffic. Compare it with the line it sits beside, not with a hypothetical rebuild. Keep what pays, pause what does not, and only then decide whether a partner belongs inside your own stack.
Frequently asked questions
Yes. Partners you already work with can be brought into the same layer over OpenRTB, Header Bidding or GAM.
Not always. Bidding sets a live price for each impression, so it tends to track what the impression is worth. A waterfall still has a place for partners that cannot bid, fixed-price deals and backfill. Most publishers run the two together.
No. MetaMediation is added to the mediation you already run. Your current setup and the partners configured in it stay where they are.
