Well to be honest it takes most anywhere from 6-12 months to even begin seeing a decent income IE 50.00 or more per month. It's a game of patience vs dedication in the end. It takes time to write promote and add to your SEO knowledge on a daily basis.
Some are more successful than others at revenue sharing websites, although I wouldn't account for making anything for the first 3-6 months. This gives you time to learn the ropes of SEO. Also if you want a good idea how well you personally will be doing wait until you have about 50-100 articles up then evaluate your work. By that point you should have enough knowledge of SEO to look back and see where you are when compared to others. Many experts will say it takes at least 50 articles before you can get a good amount of data to compare page views, ad clicks, impressions etc.
Rel did a pole once and I think it was slightly over 50% of hubbers made less than 50.00 per month..I think it was like 6% made over 500.00, and less than 1% made more than 1,000 dollars per month.
Most people use this as a stepping stone to their own websites, as then your not having to share your ad impressions. Don't get me wrong though Hubpages is great, I recently worked my schedule around doing two articles on HP per month per blog. 100% original but related articles that then can be backlinks to my blog.
Hope this helps a bit.