Android - Including more than one Advertising provider in the same application. Possible?

I'm a newbie to android. Is it possible to include more than one Advertisement provider in 开发者_如何学JAVAan Android application? (Such as AdMob and GrayStripe)...

You can roll your own, but take a look at AdWhirl the code is opensource as well. This seems to be the best solution for this type of thing

I think you can do it. But I have never seen this mode in an application, so...