I just found this site of top google adsense keyword phases, the list is large so here's the link to see them scroll down the page. http://www.freetopkeywords.com/ I found it interesting
Do we put these keywords in our site? Like I have a Proxy website can I put these keywords in my site ? or It need to have relative subject ?
just checked and conference calling still costs $24 for the top bid spot. Some interesting terms on the list.