If you can't delete the ad after selling the item then people will keep calling and emailing about it when its gone. I can't see any future in this without a delete function
It's impossible to modify the blockchain so I think it would be good to versioning system for each classified ad in the next wallet update. You should be able to mark the ad as deleted so users won't see the ad or mark it as edited so users only see the edited version.
This coin could be really huge if the devs stick around.
Right now it looks a scam. They're selling 100% of the coins before a product release. It is how cryptocoins currently operate though. You buy a bunch of scams before you finally buy a quality coin. I hope this is a quality coin.