I like PG's distinction of wealth (i.e. value) and money: http://www.paulgraham.com/wealth.html

So, while selling realizes a monetary gain, it does not necessarily create wealth also.

Here is why I still think it does create wealth:

* there is economic value in allocating resources efficiently

* (non-monetary) user acquisition increases the value of network effect driven products

* money goes to work when infused into a productive company (instead of being idle, money is invested in wealth creating assets)