Xomba is a great place to write. It has a good reputation with writers and shares Adsense revenue fairly. Not all sites do however. I recently wrote a few articles for a site which appeared to be a very good deal. The promised to share 100% of all Adsense revenue with writers if they published an article every three days. I wrote diligently and got about twenty articles on the site. My dashboard showed that I was earning 100% of all Adsense revenue however when I compared the views on my Adsense URL channels with the views I was supposedly getting on the site I saw evidence of a ripoff. There were twenty times more views than there were page views on Adsense. Fishy sounding, huh?
If you are wondering if your revenue sharing site is ripping you off there is a very easy test you can do. Log out of your account and Google your own article. When you find your article, right click on one of the Adsense ads. Don't click on the ad. Next scroll down to "properties". A box will pop up showing the URL of the ad. Click on the long URL and then scroll all the way to near the end of it. Compare the number beginning with ca-pub to the one in your Adsense account. If you are on 100% revenue sharing, your code should come up all the time. If you are on fifty percent revenue sharing do this procedure a few times by refreshing the page, say ten times. You should see your code come up at least half the time. If it doesn't there is a good chance you are being ripped off.
Note: Use whichever button on your mouse does not open the ad. It is not illegal to view the properties of an Adsense ad since it is already on your computer. You are not opening it and that is 100% legal. You are merely viewing the properties of that hyperlink.
It's sad that there are so many sites like Factoidz luring in writers hungry to make some extra money and then doing this sort of thing. Read blog reviews and search for the name of the site plus "ripoff" and see what comes up.