hehe..things I can tell you about hautelook and gilt. Let me put this in simple terms so you will understand better.
These sites work on closeout items from brand stores (think about groupon) except much larger picture with product to clear out - seasonal clearances. In one day for example products from company I work with cleared products on haute for 45K..That is just one day.
Marketing. Very simple. Email Lists. Extremely large email lists and referrals. We are talking about millions. What you need to know that each one of those stores is not started by an average guy. These are huge chains like nordstrom, macy's that use their mrkt initially to start it and then it is all about friend referrals. Super cool idea. Be big to become big. Stay tuned though - these are little fish still. In spring you will see what zappos is doing with it as well. 
