There are a few reasons why you might see the same banner displayed in different ad zones at the same time:
1) Often this can happen when more than one newly created ad zones are added to a site at once. Our system has not had enough time to populate the data, and often the ads will change in a few minutes. If they are displaying the same ad for more than an hour after adding the ad zones, please contact support.
2) We display the most clickable banners. Our advertisers can run multiple campaigns, oftern using the same banners on more than one campaign.
3) The advertiser is running a CPM campaign which allows them to set the amount of views per unique visitor to more than one.
4) Two different advertisers are using the same banner. Very often advertisers promote public offers, and the banners are provided by the affiliate, so its entirely possible, though rare, that two advertisers are promoting two different offers (or the same offer) and are using identical banners.
If it seems to be a recurring problem on your site, please contact our support platform so we can take a closer look at it for you.