So I treaded on the dark side at one point, and was hired to write a Craigslist spam application. It was pretty simple and would automatically post to all the Erotic Services sections in all the U.S. localities with randomized (a huge set of varying titles, descriptions and photos - that could all be localized specifically to where it was posting) postings, randomized emails, obfuscating the text further by using shades of black for each letter - then solving the captcha and auto-responding to the email to publish the posting. It would do this every 20 minutes, 24/7.

The results for spamming adult dating affiliate links was pretty interesting. On average it would earn $1k a day, with most holidays jumping up to $2k a day. One very religious holiday in particular (won't mention which one to single any group out) brought in $3k. In one single day.

As long as spamming people with affiliate links will work, and makes them money - someone will do it.