great support, a good sales mechanism, and making product demos are all very important as well. if it's some new game and people can't tell you about problems they (and possibly many others) are having, then you can't fix the problem. if they can't buy it easily, most will give up. if they get to play a little for free, if the get a taste, then they'll want more.
with the right combination of marketing, you can achieve success. but the same level? ooo, hmmm... it would have to be a really good game. just like music sales for web-based indie musicians and video sales for web-based videographers.