We had a guy locally that listed a Delta dust collector for $50. Claimed he just didn't have the room for it any more. I emailed him stating I would buy it but didn't get an answer. I tried again the next day and still no answer. I figured that he was just too lazy or sorry to take down the post for an item that was already sold. So.....
I emailed him every day after that asking if it was still available. After about 3 days of that he finally deleted the CL posting. Good for him as I was prepared to email him every day until he deleted it no matter how long it took. I was a programmer before I retired and I could have automated the whole emailing process so that I didn't have to do anything to send the emails but start up the process and let it run for as long as it took.
I hate it when people don't remove the ads for things that have sold.