Given the fact that Adsense does not allow you to sign up for an account using a subdomain of tumblr, I would imagine that even if you sign up with a different domain and then create and put Adsense on your Tumblr page, you will be penalised. So my question is, what's the best alternative of Adsense which allows adding ads on free-hosting websites?
Chitika : <a href="http://www.chitika.com/" rel="nofollow">http://www.chitika.com/</a> - low cpc, but allows you to put ads on subdomains.
Clicksor : <a href="http://www.clicksor.com/" rel="nofollow">http://www.clicksor.com/</a> for contextual ads.<p>Or just buy a domain. It costs around $10 { .com }.