Yesterday I discussed how it's not a good idea to rotate banners if you don't have a lot of traffic. Instead, you can try putting multiple ads in the space where a full ad would go. This will help you determine which advertisers work best with your site.
You don't want to go nuts including dozens of ads on your page, but you want to give the handful of ads you'd like to test an opportunity to be seen as much as possible. Since some of the spots in the grouping might do better, it's best if you can shuffle the placements within the group.
When you do this, you want to keep the larger ad size in mind and select the smaller ads so that they fit in the space of the larger ad as nicely as possible. That way if you want to switch to the larger ad, you won't have to make any major changes to your template.
You may not think you'll want to switch to the larger ad, but it's a good idea to keep it available as an option. Advertisers like the larger ad sizes (336x20, 728x90, 160x600, etc) and you may have an opportunity to display just one big ad if you get an offer. You may also find that one of the smaller ads does significantly better than the other smaller ads in the group, so you can experiment with running it at full size to see if you can improve the performance even more.
The reason the bigger ads are more sought after is that their size captures the users attention. What we're going to try to do is group together smaller ads close together so that they visually take up a similar amount of space. That will get the user's attention, and they will have an opportunity to review different ads. Within a couple thousand page views, you should have a good idea of which ads will get the highest click-through rate. After around 50k page views, you should start getting a good idea of which ads will have the best conversion rate.
This post covers some examples of common ad formats and how to break them up into groups of smaller ads. This should help you come up with other ideas for ad sizes you have on your site.
728 x 90 Leaderboard
The leaderboard is a very popular size that many people use in their headers. Instead of using one leaderboard, you can use 5 different, equally spaced 120x90 pixel ads as shown below.
468 x 60 Banner
This was one of the first popular banner formats and still widely used. Below you can see different variations using smaller ads which you could use instead. The grey background denotes the full 468x60 banner size for clarity.
336 x 280 Large Rectangle
The Large Rectangle format (336x280) generally performs very well because of its size. It does well within or near the main content of your site. When you're testing you see you have a few options.
Four 125x125 buttons and 10 150x50 buttons are shown in the example on the right. You can also use 2 columns of 120x90 ads with 3 rows. Depending on what size banners are available to you, you might be able to come up with other options.
You just want to make sure it looks visually appealing. In some cases 10 banners in this configuration may not be a good idea, especially if you have other ad slots on the page. It may perform well on some sites but not others.
The skyscraper is another common format. As you can see you have a few different options and you can combine different sizes if you need to. The image on the right shows 3 different configurations.
The 160x600 wide skyscraper is more in demand by advertisers. Unfortunately there aren't many other standard ad format with a width of 160px. You could use 150x50, 125x125, 150x150 or anything else you can find that will fit and not look out-of-place.
The hardest part of earning revenue with affiliate banners is knowing which ads will work best. The only way to find that out is through testing. These tips should help you find out which advertisers/ads may have the most potential on your site.