2) Product reviews (with pictures).
Click and shines are great but since the way a car will look in the end depends so much on prep and even the car, a shiny picture doesn't guarantee that the product is better than another. One thing I've learned from this site is that a properly polished car with nothing on the paint can shine way more than an a car with paint in average condition with an expensive LSP. Some cars have paint that looks a mile deep without wax so just because it looks great in the picture doesn't mean the wax did that. So reviews of "this looked way deeper than anything I've used before" or "more of a hard candy shine" are quite helpful.
Pinnacle Souvern looked flat on my car till I went over it with a good 2 step polish, now it looks like an expensive LSP should on the car. So if I had posted pictures of the car with PS on it before people might have thought it wasn't that good.