QuoteThe last time Jerry and Marge played Cash WinFall was in January 2012. They'd had an incredible run: in the final tally, they had grossed nearly $27 million from nine years of playing the lottery in two states. They'd netted $7.75 million in profit before taxes, distributed among the players in GS Investment Strategies LLC.

http://highline.huffingtonpost.com/articles/en/lotto-winners/

That story reminded me a lot of buying Google AdWords.

Just like with lottery tickets, you can't predict exactly which clicks will produce a profit. But if you understand the system and its patterns you can do a lot to improve your success rate.