Right, but it's not sales in the sense of "lets convince stupid people to waste money by giving it to us", it's more in the sense of "trust us, we're smart, have a good strategy and good past performance". Of course, the average hedge fund under-performs the market (for a particular measure of performance), but rich people might have other investment goals (the chance of finding alpha & beating the market, diversification, negative beta (anti-cyclic returns), ...). Same as with casinos/lottery, they need little sales, people know it in average underperforms just keeping the money, but you're not gambling for the average, you're gambling for the variance.
Interesting point, but given that the average performance is ... average, most rich people would be better off investing in an inside edge on a deal. Which is what I suppose they do.
