I used Yahoo! Pipes in a somewhat greyhat way. I started pulling in data from Reddit's RSS feeds for certain subreddits and using that to create and post content for fairly spammy Twitter, Tumblr and Facebook pages. I'd parse the titles (for example, change things like "cake day" to "birthday") and adding hashtags at the end.

You could ensure only top content made it by setting a minimum karma limit. It was a way of producing content 24/7.

I only did a couple of trial pages to test out the concept -- I never made any money from it nor had any intention to monetize -- but I'm almost completely certain that it was a method used by dozens of blackhats to make autoblogs for the purposes of ad revenue. You could even fake a comment history or have a "unique" title by selecting the top comments from the Reddit posts. Once you have one recipe down, you can just copy it for other subreddits. And there was an endless amount of hyper-focused niche subreddits that you can instantly plug into.

Fun times.