You can use a "bait & switch" method to trick people into doing something that they actually think is for their benefit when it really isn't. For instance you could.... well, nevermind, you already did.

I also like this article: http://registeredrep.com/advertising/

Now, now, you weren't supposed to notice that!

Fear mongering always works for me... The products fly off the shelves to the point where I mark em unsolicited.....