A recent revision of Google’s AdSense Program Policies now enables you to place contextual advertisements from non-Google services along with AdSense ads on the same page. Till now you weren’t allowed to display ads from third-party services like Chitika eMiniMalls, IntelliTXT, Kontera etc. on the same page as AdSense ads.
However, restrictions still apply regarding the nature of ads shown. You can use any of the other services in conjunction with AdSense, as long as their ads don’t mimic the AdSense ads i.e. the visitors shouldn’t confuse them with AdSense ads.
In other words, services which by default, show ads in the same format as AdSense ads won’t be permitted. If on the other hand, your ad service provides you ad customisation tools with which you can alter the format of the ads (e.g. add a border, alter the colour palette) you are free to place their ads parallel to AdSense.
According to the Jensense Blog…
I have had a few questions regarding whether using the same ad unit sizes would constitute having the “same look and feel”, and some others are reporting that using anything in an ad unit in the same style as Google’s (such as using something that looks like YPN) would violate this policy. Fortunately for publishers, the answer is no, just the fact the ad units share the same styling (as nearly all contextual ad networks do) will not break the policy as long as you take care to change the color schemes used by each.
Bottom line, this means you can use the same ad unit sizes from two different programs, as long as there are clear differences in the color scheme (and things such as borders or backgrounds) used by your Google ads. It is also worth noting that proximity of the competitive ad units to each other also comes into factor when making changes to your site by adding competitive ads. I asked Brian Axe from AdSense to clear up just how different the ad units need to be so publishers do not inadvertently violate the policy.
Services like Chitika & Amazon serve ads in a different format by default – so you can go ahead and implement them directly without any alteration as such. You might require a bit of tweaking in case of IntelliTXT & Kontera.
As for YPN ads, be careful – it’s against Yahoo’s program policies to place contextual ads from multiple sources on the same page. But one might expect Yahoo to follow suit after Google’s policy revision.
All in all, the change is actually for the better as it’ll allow placement of ads of competitive products on the same page – and not just from a single source. All you need to ensure is that any other ads you use (whether contextually targeted or not) do not resemble the AdSense ads run anywhere on the same site.