I've usually bought a watch on the strength of what I see as being accurate and appropriate for my wants at the time, and then read a review of it because it was an excellent rep. An example being the TAG Link Chrono which I was the first customer to post about in these forums, having bought it less than 30 minutes after TTK advertised it!
Likewise I decided to track myself down a Breitling Seawolf Ti and within a day of doing so the buyers' guide appears listing it as top Breitling rep!