Monitor110 recently shut down after raising $20m over three rounds. One of the co-founders wrote a portmortem of Monitor110, highlighting 7 mistakes that the company made:

1. The lack of a single, “the buck stops here” leader until too late in the game
2. No separation between the technology organization and the product organization
3. Too much PR, too early
4. Too much money
5. Not close enough to the customer
6. Slow to adapt to market reality
7. Disagreement on strategy both within the Company and with the Board

(found via Brad Feld)

At the other end of the spectrum is a post mortem of a bootstrapped two person startup that shut down last month after building for 1.5 years but not raising any venture capital. This founder’s lessons learned are more tactical, but no less important:

1. If your idea starts with “We’re building a platform to…” and you don’t have a billion dollars in capital, find a new idea. Now.
2. It’s a marathon, but it’s a marathon made of sprints
3. Initial conditions matter. A lot.
4. Developing in a vacuum never works.
5. Beware the chicken and the egg.
6. Prototype any 3rd-party libraries that you’ll be depending upon, before you base your product on them.
7. If you’re doing anything other than building your project and getting users, it’s premature.
8. The product will take longer than you expect. Design for the long-term.
9. People have an incentive not to crush your dreams. Take everything they say with a grain of salt.
10. Know your limitations.

(found via Brian Green)

I would recommend entrepreneurs to read both posts.

“Those who cannot remember the past, are condemned to repeat it.” — George Santayana

Read more of Jeremy on his blog.