When it comes to sites you are considering doing link trades with, etc do you put much wieght on the stats from places like Alexa, Compete, etc?

I was always under the impression that these types of sites werent that reliable with their stats but was just chatting with a freind on ICQ who was trying to convince me that these are used quite a lot in mainstream to gauge a sites traffic.

Have these types of stats improved over the years so that they actually are more reliable than they used to be or are they just as bad now as they have always been?

Regards,

Lee