Masssive Traffic Does not Always Mean Massive $$$
I know someone who spun his wheels developing great one word domain names. Tons of type-in traffic, plus thousands of existing links. Those domains were traffic monsters, which is why he purchased them.
Unfortunately the domains had zero to do with shopping or products. Consequently, he had over a million people a month downloading his jpegs and information and using them for school projects, literally making pennies a day from those sites.
Traffic doesn't always mean money. That's why it's important to think about cultivating traffic that clicks.
What kind of traffic clicks?
Your mileage may vary, and I'm interested in hearing your experiences.
My most successful sites are those in which people are at some point of a buying cycle.
What kind of traffic does not click
In my experience, forums and how-to sites don't do that well. Makes sense when you think about it. People are generally there for community or information. Shopping is nowhere near on the agenda.
Turning around a how-to site
Nevertheless, that doesn't mean a how-to site must remain a money-loser. Here are some ways I monetized a how-to site:
Tools, Products, and Services
Every How-To Project requires tools. Articles about the tools people need have generated good clicks for me in terms of EPC and CTR. If you want to stimulate AdSense clicks, talk about the tools needed but DON'T talk about the places people can purchase them. Let your AdSense ads do the talking.
If you have a gamer site, what you can do is review graphic cards, monitors, gamer systems, parts for a Mac gamer system (don't forget the niches!), etc.
Talk about the high quality products, then talk about the CHEAP quality products. If you talk about it, they will Clickety Click-Click-Click!
Where to Buy the Tools, Products, and Services
This one is a little tricky and depends on how far to one side or another you tilt your hat.

But it has worked well for me. I have had good success in naming places one could purchase the above mentioned tools and products in different towns around the country. Make sure you spell out the state or province name so you show up in those local searches.
Make use of sidebars
This has about 60% to do with SEO and 40% with AdSense. I've had good experience using sidebars to introduce longtail keyword parts into an article page.
For instance, if you have an article about Cheap Flights to Cancun that is discussing ways to hunt down those flights, tips and tricks, you can also place a sidebar listing Major Cities that people would be flying out from to reach Cancun (plus give an excuse for more pages related to those cities or any number of other solutions).
Then you'll get queries from people looking for Cheap Flights to Cancun from [insert major city here] and when they get there the only spot telling them WHERE to get Cheap Flights to Cancun from [insert major city here] is in your AdSense ads. Clickety Click-Click-Click!
What are some of things you do to make sure your EPC and CTR stays high?