Banner ads
Banner ads are image ads placed in fixed-size slots on a web page, such as 300×250 or 728×90, and are usually bought per thousand impressions.
How it works
A publisher reserves rectangles of standard sizes on its pages. When a page loads, each slot requests an ad, and an ad server fills it with a creative of exactly that size. Each size is effectively its own market: an advertiser who supplies one size can only compete for slots of that size, and the rest of the inventory goes to someone else.
Banners are seen often and clicked rarely. Low click-through rates are normal for the format, so banner campaigns are better judged on cost per result than on CTR alone.
Example
You buy 500,000 impressions at a $0.30 CPM: cost = 500,000 / 1000 × $0.30 = $150. With 400 clicks, CTR = 400 / 500,000 × 100 = 0.08%, and the effective cost per click is $150 / 400 = $0.375.
On UluMob
Banner campaigns are priced per thousand impressions (CPM) or per conversion (CPA), with default floors of $0.05 CPM and $0.50 CPA and a $15 minimum daily budget. Four sizes are sold: 300×250 on any device, 728×90 and 160×600 on desktop, and 320×50 on mobile. Each image must match its size exactly and weigh no more than 150 KB, so upload every size you have.
A CPM impression is billed when the banner document actually loads in the page, not when the slot requests it. You can add your own third-party impression tracking URL to each ad.