Every contribution is worth one point, or are certain things worth more points? And what does one get if he has, say, 1000 points? A fridge? A new Ferrari?

some are worth more than others. the kinds of contributions that are more meaningful (articles, etc) are worth more.
at 1,000 points i get you a free t-shirt (as long as they are not achieved through spammy methods)
UPDATE => Nov 11 2008 - we do NOT give out free shirts anymore (we did this for a few weeks and stopped in 2007).
Wow, a Chess.com T-shirt! That's even better than a Ferrari!
You'd better print that shirt already, since I'm only 984 points away from 1000 points! (983 now!)
There is always the option to go to the "Member Store" and buy your own Chess.com shirt. There are many high quality shirts there at reasonable prices.
I am intending to buy some Chess.com shirts and hats
Matt, that's pure spam! You're just advertising the Chess.com Store now, in a topic that isn't at all about the store! How dare you! I'll tell Erik unless you buy me one of those shirts too!
Member Points: Chess.com keeps track of all of your contributions to the site such as comments, blog posts, forum participation, articles, etc. Each contribution counts for points. This helps members know how involved each other are in Chess.com!