There are just as many ways to profit from twitter as there are from a regular web site. Most people use twitter to build a brand and grow the traffic to their money site. If you are ready start making money from twitter it may be best to start a site that has a monetization model that can be fed by social activity. There are some pay per tweet sites that do pay and I have used them in the past, they do in fact pay out. However, they spam up your stream and take away any focus that you have been building with your various twitter accounts.
Hope this helps.