No, in fact it is a new source of income for us. We just started at the end of September. We also receive funding from sponsors, members of the admin portion of the system (the admin side posts content - no AdSense on those pages, AdSense ads are on the pages that are free for the public to view), and some subsidy. That sounds like a huge amount, but we have several programmers, trainers, help desk people, and of course management (and of course hardware and connection fees). The site is not-for-profit. The AdSense is just to help us recoup some of what we spend.
In november I finished the month with 115. yay!! That means extra christmas money...can never get ahead on bills...