Ask HN: People who acquired a startup: How did it go? What did you learn?

I'm interested in finding out the experiences of people who've worked on the buying-side of a startup acquisition.

1. Why did you (or your company) decide to buy the startup? What was your involvement?

2. How did you handle integrating the startup into your processes and culture?

3. Were you able to retain the right people?

4. How did it turn out in the end, and what did you learn?

EDIT: Formatting