A rather new company called Buy Blog Comments is promoting its service, offering to leave spam comments on other blogs.
For just under $20 you can get 100 comments. If you're looking to completely waste your money, you can get 1000 comments for about $200. Based on the company's own description of its service, there's a team of humans behind the curtain that will leave relevant comments on relevant blogs, taking extra measure that these spam comments will not be deleted. Buy Blog Comments comes from the Developer Hut Network, which is also the parent company for other spamming services such as Funny MySpace Comments. We've all seen spam comments on blogs, and several bloggers and blogging services take measures to prevent the proliferation of this type of spam.
This business model rarely works out in the long run, especially when you're dealing with effective communities such as Digg. A similar service that has emerged out of the ashes of Adder Robot, TellyAdder.