When considering ad revenue, mod payments, and treasurer payment accruals, the forum is certainly operating in the red. The forum has the ability to operate this way for many years/decades, so theymos may not be concerned.I do think that the forum should at least allow targeted ads, which I would anticipate increase total ad revenue.
Of course I'm not in the same level as you guys are, on commenting about the forum and its revenue but i would like to say about
targeted ads... they are never beneficial in long run. I personal loose trust on any website running targeted ads. May be forum will gain some revenue but how much user base it might loose?
I'm sure if theymos focuses on ads, it wont take long for any other forums like "stackoverflow" to take over all the bitcoin related technical discussion.
If current ads revenue is enough to pay expenses and bitciontalk's BTC stash not depleting very fast.. introducing ads for profit or additional revenue... i doubt if it will be beneficial in the future.
Ad free and trust worthy content is the still the key... newspapers and many media outlets still quoting posts of Satoshi, Wan Dai and Hal Finney from bitcointalk and i wish it stays the same way.