What type of features can you charge for in classifieds?

[ChadsMach1]

I have been checking out some of the posted sites from members trying to get a good idea of what kind of features can be configured as a charge. So far, all I am able to find is a charge to bold, and highlight and italic. Are there anymore that are standard, or are these all defined by the site admin by configuring the script? I want to make all ads free, but try to upsell some features. Any help is appreciated.

[Chuck S]

You have those and of course you can charge for the ad itself by placing a price for ads via each category along with those bold italic and highlight costs

Thats all there is