This classified ad site is a paid service site, you determine your prices via the site admin area.
All users who register for the site are pending until they purchase an ad package. Once they purchase an ad package they will become active until their ad expires.
They can always log into their account to add more pakcages at a later date.
If you would like to offer a free ad for your customers you will need to do it manually.
This is so people do not abuse the website.
To give members a free ad, login to the siteadmin and find the pending member and click on them. Next hit edit. Under edit you are going to click on activate. A new screen will load allowing you to pick a package for this member. After you have selected the package, the member will get an email notifying them of the package and when it expires.
For paying customers, this site uses PayPal and stormpay's IPN system so adding credits via the payment processors is automated.