I think Adam's mistake here is to go too much by the numbers. He presumably has numbers that show that Quora ends up net ahead if they force people to create accounts to read answers. He grew Facebook very effectively by following the numbers. But he may not realize how different this case is from Facebook's. It may well be that for a site like Quora, at this stage in its life, users are not all equal. It may be a mi…
Quora is now 3 years old and has taken $61 million from investors. Are there any numbers publicly available to show user growth over this period?
I believe they're simply optimizing the wrong variables. It has certainly driven me away. I use the google personal block list, and Quora was among the first sites to go on it.