[fnordfnordfnord]

>Why would you sell something you could make profit on if you kept it for yourself?

This question has been answered an immeasurable amount of times.

Several groups organized ASIC production projects. Avalon, BFL, and a couple others I can't remember. None of these initial groups had the capital to finance the NRE (Non-Recurring Engineering) for the ASIC, nor were traditional venture capital sources willing to do so. The ASIC production process has a relatively a high NRE, but low incremental cost. So, Bitcoin folk organized and participated in pre-sales to finance the NRE for these ventures. They had to sell the things or they would never have been able to afford to produce the initial units.

Additionally, even if some group would've had the capital to spin their own ASIC, it would have been a bad bargain for them to monopolize ASIC mining when competing against FPGA miners. Their capacity would have been limited to some fraction of the much smaller total network capacity in the FPGA era. Also, a single party swamping the network would've earned enmity from all of the other miners and Bitcoin users who could possibly have forced them out of the network, rendering their investment useless.