If you shop online, do you read the customer reviews for items under consideration? Do you find them helpful when deciding whether to purchase an item or to determine fit, quality, etc?

I always read them (almost a guilty pleasure). Sometimes they are quite helpful and other times I find them hilarious.

I just read a recent review at GAP.com and the reviewer questioned whether the fit model was a pillow. *chuckle*

Bonus: Do you ever leave feedback after purchasing an item?