I made ~$4000 last month by arbitraging crypto currencies on 3 markets.
I use a bot to do the work for me, but I monitor it very closely and I spend a lot of optimizing the old code. I don't have much money on the exchanges because I don't trust them but I could make much more if I wanted to risk more.
tl;dr Someone hacks WordPress websites and includes strange .js files that a) lead to fake Flash downloads that install a botnet on your PC and b) abuse your browser to get URLs from a Google search.
Bitcoin is not the best thing for recurring payment. But it would be great to pay a year in advance with Bitcoin - and yes that solves chargebacks or fraud issues.
I use a bot to do the work for me, but I monitor it very closely and I spend a lot of optimizing the old code. I don't have much money on the exchanges because I don't trust them but I could make much more if I wanted to risk more.