"Why go fast? Many reasons:
- First mover advantage is important.
- There is no such thing as a unique idea. I guarantee that someone else has already thought of your wonderful web service, and is probably way ahead of you. Get over yourself.
- It forces you to focus on the key functionality of the site.
- Being perfect at launch is an impossible (and unnecessary and even probably detrimental) goal, so don't bother trying to achieve it. Ship early, ship often.
- The sooner you get something out there, the sooner you'll start getting feedback from users."