Over the years I've heard of people setting up a large number of sites (100+) that each bring in a tiny bit of traffic but together bring in a lot of income. Is this still possible in today's seo environment (post Panda/Penguin, etc.)? I mean it wouldn't seem practicable to do link building, content promotion, etc for this number of sites. I'm not opposed to doing black hat tactics but I want to build a business for the long term. Any thoughts on how to build an affiliate business like this?