But, just to save you the bother:
a) one guy started it, but it is not a one-man show, nor has it ever really been b) the data was sourced (Wikipedia-style, you might say) on Usenet, back in the pre-WWW days. Since then, the number of sources has multiplied. c) it goes to Amazon, who bought the IMDB back in '98. d) Of course not. He's a VP at Amazon. There is a staff (of unspecified size) working on IMDB.
1. get users to submit a bunch of content to you in an open system for free
2. close the system and claim ownership of the database that your users helped create
3. profit!
"...asked if the sale had made him and his group of volunteers rich..."
Which is why being bought out by Amazon is about as good as it gets. They usually find a good way to manage the post acquisition period, most other companies botch that completely.
I think having the founder still working there and not jumping ship as soon as some vesting period is over is a good advertisement for being acquired by amazon. Also it's still it's own site, could have easily been rolled into amazon in an attempt to push more DVD sales over the years.