This is one approach, ala' Warren Buffet - put all your eggs in one basket and watch that basket very closely.
Is anyone getting traffic from Squidoo yet?: "I play the Adsense game, and build lenses to drive traffic to my Adsense sites. Reason? Because if you build a really tightly focused squidoo lens on a search term that has really low competition, you can get your lens ranked #1 for that search term in just a few days. Google is eating up squidoo right now.
So if you want to use your lens to drive traffic to a 'money site'. Build one around a tightly focused keyword/keyword phrase that has little competition and then you'll see the real traffic."
You'll note in the above that this is essentially niche marketing (see the phrase "little competition").
Of course you could also have many "tightly focused" baskets...