What happens in one request
When a visitor loads a page carrying the UluMob tag, the zone asks for an ad. In the time it takes the page to render, the engine:
- Identifies the visitor's country, region, device, operating system, browser and language.
- Discards the request if it comes from a known bot or from an IP address requesting the same zone faster than a person browses.
- Collects every active campaign of the zone's format that targets this visitor.
- Removes campaigns that blacklisted the zone, hit a frequency cap, are outside their schedule or day-parting hours, or reached a conversion cap.
- Ranks the rest by eCPM and picks the highest bid that still has budget and balance to pay.
No money moves at this stage. CPM is charged when the ad renders, CPC at the click and CPA at the postback.
One scale for every pricing model
A CPM bid and a CPC bid are not directly comparable, so the auction converts each bid to eCPM: the expected value of a thousand impressions.
| Pricing | How eCPM is derived |
|---|---|
| CPM | the bid itself |
| CPC | the bid times the expected click rate for the format |
| CPA | the bid times the expected conversion rate |
| CPV | the bid times the expected view rate |
That way a high CPC bid on a format where people click often can outrank a modest CPM bid, and the publisher earns from whichever buyer values the visit most. Bids below the zone's reserve price never enter the ranking, and a zero bid never buys free traffic.
Fixed bids and smart CPM
You choose how a CPM campaign pays when it wins.
- Fixed: you pay your bid on every impression you win. Predictable cost, simple to reason about.
- Smart CPM: you set a maximum and pay one cent above the next best eCPM, never more than your maximum and never less than the zone's reserve. When competition is thin, you pay less. When it is strong, you still compete up to your limit.
Equal eCPMs win in random order, so no campaign gets a permanent edge from the order it was created in.
Bids by country, filters by zone
The campaign bid is a starting point. You can override it for individual countries on each ad, so one campaign can bid more in the markets that convert and less elsewhere. Zone blacklists remove sources that do not perform, and whitelists restrict a campaign to the zones you have already proven.
Floors are visible before you spend. The traffic volume page shows minimum bids and available volume by format and country.
Budgets the auction respects
A campaign that cannot pay does not win. Before an ad is served, the engine checks that the next charge fits within your daily budget, your total budget and your account balance. If the top bidder cannot pay, the next one in line serves instead. The final charge is applied atomically, so two requests at the same moment cannot spend the same dollar twice.
Budget spreading paces delivery across the day instead of spending it all in the first hours, which matters most in large countries with steady traffic.
Why this matters to you
For advertisers, an open auction means the price reflects demand at the moment of the impression. For publishers, it means every visit goes to the buyer who values it most, and their revenue share follows that price. Start a campaign or read how CPM billing works.