I've been having niches sites for 3 years and the result is great. Having and average of $120 daily from 40 niches sites is good enough especially if you are living outside US.... The latest version of Xfactor's adsense authority site explains a lot about making a big website. I followed the instructions and started last December. Now I have around 670 articles and the result is more than I expected. The site is averaging $45 to $60 per day. So, I can conclude that authority sites, though requires tons of work especially in writing, can pull a total package from Google. Now I am turning some of my niche sites to become authority sites. I am targeting 5 authority sites before this year's end while maintaining or even adding more niche sites......
So, what niche sites do you own? What fields? Can you tell us? And congratulations on such good profits already.