I buy a lot of my clothes online, mainly because I can usually find my size, whereas I can never find them at the department stores. (Try going to Nordstrom and find a pair of size 25 True Religions, I guarantee they won't have it.) I'm an avid shopper at Revolveclothing.com and Shopbop.com. If those didn't exist, I wouldn't have half my wardrobe. Anyway, using this handy little site, I don't have to browse through all the separate sites and if I'm looking for a little black dress, I can do one search and have millions of options!
Another fun thing is you can create "looks" which is way too entertaining for me. I love putting together these outfits. I put together a little outfit that I would wear to my bachelorette party (which by the way, will be in VEGAS!)
Unfortunately they don't have wedding gowns yet, just a few from J.Crew and Ann Taylor, but you can still browse through the shoes and jewelry. Here's a simple wedding look that I created: