I said it before and I'll say it again -- charging people looking for jobs is ridiculous. I don't know who the kid in Houston looking for an OCaml internship is, but how the heck does he have $100 to spend on this?
Considering the job you have has a massive impact on your personal happiness it makes a lot of sense to improve your odds of finding the right company to work for. The cost of careers.stackoverflow is nothing compared to the cost of actually taking an interview (easily 8+ hours). If because of stackoverflow you can get by with one interview less it's easily worth it.
Besides, if you have 3 great offers on the table I'm sure you'll be able able to negotiate a $100/year raise to recoup the careers.stackoverflow investment.
I believe students get SO careers memberships for free. They only charge non-students. I think they mostly want active job searchers, but $100 does sound a bit high if I just want my resume out there.
No matter how many times you say it doesn't make it right. Charging to look for average crappy jobs? Sure, that's ridiculous. Charging to essentially filter the jobs down to a subset with a high likelihood of being above average and excellent jobs? Well worth $100.
I can get a crappy job off Dice anytime and spending money to do it would be a waste. Spending $100 to have a chance at a great job where I'm actually happy? That's an investment likely to have pretty good returns.
To spend $100 in order to find a better job, I think is worth it. $100 isn't a lot of money, especially when you consider it an investment into your future.
(1) The $99 fee is paid up-front, not when (if!) hired.
(2) There is a limited-time price reduction (to $29) for 2009.
(3) They advertise a 90-day, no-questions-asked money back guarantee.
Besides, if you have 3 great offers on the table I'm sure you'll be able able to negotiate a $100/year raise to recoup the careers.stackoverflow investment.