I've seen this many times from forums etc. And I'll share my personal experience and what I think of it.

Firstly, I don't think it'll last too long. Google or Yahoo! may be targeting them for copyright violation, and quite possible an automation of their searching.

Secondly, almost anyone can code this, and just a simple line, I don't like it at all. If I want either, then I'll go to their URLs.

Overall, I dislike it.