You can tell a lot from looking at the physical layout of a website. Look at the following websites selling a wide number of products:
The Popular Life: How to Become Popular Pickup Women Online - Online Dating & Pick up Resources Build Muscle Bodybuilding Muscle Building Gain Weight Hardgainer (warning: pop ups)
Easy Money Online - Make Money Fast - TheRichKids
Notice anything familiar? The unusually large font. The random highlighting of words. The testimonials. The links to BUY NOW.
All of these websites also have several other things in common:
What they sell is complete and utter crap.