[karmawhore]

I like their philosophy that you can make changes and push them often so that you do see immediate gratification that your work means something. A typical non-startup developer's work could take years before it ever hit a desktop.

While the stock options that others mention is a motivator, typically companies use options to buy down your salary. You would make $120k, but, we're going to give you $90k + $30k in options that could be worth more than $30k in a few years. Pre dot-bomb, extremely greedy employees would work for a .com, trade huge amounts of salary for options and live frugally until the IPO. I can think of one guy that worked for Real Networks for a few years that took 66% of his pay in options which were underwater when his options matured.

Options are a payment type and are a gamble on the employee's part. The employer believes that shared ownership will also motivate employees, which makes those options worth more.