if you want to become an affiliate marketing to get Bitcoin find a company to work with,
for example my local exchanger offer us an affiliate link and we will get 5% from their fee,
(it will works if they registered under your link obviously).
how about search it in here 'Service Board':
https://bitcointalk.org/index.php?board=52.0as far as i can see,i found something like that in there.but i can not guarantee about it,
because many people have been scammed by those type of works,
by the way,you can not become an affiliate with Bitcoin,but find a work with a company or people that pay you in Bitcoin.