Good discussion
Both my sites are travel related - one site gets 60,000+ uniques a month, but has no adsense. The other site gets 3-4,000 uniques a month, most from the forum - the problem is very few people click on the links in the forum, and Adsense is used on a few other pages within the main area of the site.
I need to take what you have all said and look at improving this. I don't think $100 a month is impossible though - I've earnt $54 in February, just needs some more thought.
Thanks
Darren