Google Adsense had expand their market to Bulgaria and Serbia. Thus, is an opportunity for us.
"Two more languages -- Bulgarian and Serbian -- have just joined the AdSense for content family, and AdSense for search has also launched in Serbian. We know that web publishers in these regions have been waiting for for a long time -- thank you for your continued patience.
To get started with AdSense for content or AdSense for search, log in to your account and follow the wizard located under the AdSense Setup tab. If you don't have an account yet, you can sign-up for AdSense in just a few minutes."
To know more about Adsense, read What is Adsense