Easy way for the search bots to find paid links

As I was poking around the source code of a site I saw this line

!— 3 links expires 9/30/07—

If I was a search bot I think that just might tip me off that those links were bought and should not be fully trusted.  It is no secret that I am not an angel in the eyes of the search engines, but even I have to say that it just too lazy/stupid when someone puts the actual link expiration in a comments tag.

PS – If you are interested in buying links make sure you take a look at that sites source code.  The link should not be using javascript or iframes.  Also it is generally a good idea to take a site they are already linking to and see if it shows up in the Yahoo backlink search.  Better shut my mouth now before Captain Sprite comes flying along