[jamesrcole]

Good article. One small thing that wasn't clear to me is

The feedback you get from engaging directly with your earliest users will be the best you ever get. When you're so big you have to resort to focus groups, you'll wish you could go over to your users' homes and offices and watch them use your stuff like you did when there were only a handful of them.

Why can't you do that once the company gets to a certain size? I don't have any experience with these things, so it's not clear to me. Surely there must be some better alternative than focus groups.

[arkades]

Sample error.

When you had 100 users, it was feasible to get detailed feedback on 90 out of 100 users. When you have 1.5m users, you cannot get detailed feedback on 1.35m users. Dealing with much smaller fractions of your user base, sampling error grows into larger and larger an issue. That's not to say there aren't wonderful statisticians working on sampling issues, but fundamentally it's not the same as actually interacting with the vast majority of your user base.