Integrating a wall is a day of work and a long-term dependency. These are the questions worth asking before that day, and what a bad answer costs you afterwards. Ask them of us too.
Inventory
1. How many offers will my users actually see? Not the catalogue size — the number available to a user in the countries and on the devices you have. A quarter of a million offers is meaningless if forty of them are visible to a German user on Android.
2. How deep is it, and how resilient? Depth matters more than the headline number, and so does what happens when one source of demand has a bad month. Ask what the wall looks like when that happens.
3. Can I see it before I integrate? Any provider should be able to show you a live wall for your country and device in under a minute. If they cannot, ask why.
Crediting
4. How do conversions reach me? The answer should be a server-to-server postback to a URL you control. A client-side callback is a wall that can be credited by anyone with the browser console open.
5. Is it signed, and how? You need to be able to prove a postback came from them, with a secret only the two of you have. "We will send from these IPs" is not a signature — addresses change, and an allowlist proves where a request came from, not that it is genuine.
6. What happens if my endpoint is down? There should be retries with a schedule, and a log you can read afterwards. If a conversion is dropped because your server hiccupped for thirty seconds, you are paying for their design decision.
7. Do you send reversals? Advertisers claw back fraudulent and cancelled conversions. If a provider does not pass those on, one of two things is true: they are absorbing them, or they are not telling you about money that has already left. Ask which.
Control
8. What can I filter? Categories, countries and a payout floor are reasonable — they all describe what an offer is, which is your business, because you know your audience. Be suspicious of a filter that hides whole slices of the catalogue at once: a wall with less on it is a wall that earns less, and that cost never shows up as a line on your own dashboard.
9. Can I make it look like my product? Colours, layout, density and your own heading, at minimum. A wall that looks like somebody else's product inside your app costs you trust at the exact moment you are asking users to do work.
Money
10. When does earned become payable, and how do I get it? Every provider holds earnings for a period — that is how reversals are absorbed. What matters is that the period is stated plainly, the destinations are ones you can actually use, and the minimum is not so high that a small publisher never reaches it.
11. What do you show me about my own numbers? You should see every click, every conversion, what each one earned, and every postback attempt with its response. If reporting stops at a daily total, you cannot answer a single user's support ticket.
The one that tells you the most
12. Who do I talk to when something is wrong, and how fast?
Everything above is a feature list, and feature lists are easy to write. The day a payload format changes, or a conversion goes missing that a user is angry about, the only thing that matters is whether a human answers you and whether they can actually see what happened.
Ask a support question before you integrate and time the answer. It is the most honest signal you will get.
What a good answer sounds like
Specific. Numbers, field names, timings, and a willingness to say "we don't do that" out loud. A provider who answers every one of these with "yes, absolutely" has not understood the questions.