Adsense on wordpress.com blog

I tried to place an adsense unit into the widget of a wordpress.com blog. But it didn't seem to work. Does anyone know how to do this properly?

 

you can't use adsense on wordpress.com pages as they wont allow to do that according to their setup ( free blogs )

http://en.support.wordpress.com/advertising/

 

Thanks, that is why....
.... Is there any possibility to run ads on free wordpress blogs. Like amazon. It sounded a bit ambivalent on hint to me.

 

simply remember http://yourblogname.wordpress.com offers limited option for the bloggers. No javascript code, specially any adsense code in your blog. You can add google adsense code in your paid hosting blog.

 

I start to like blogspot more then wordpress ...

.... OK wordpress has got some other nice features, I admit.

 

You can't place Adsense on a wordpress subdomain