Classified listings appear in order of ad renewal date. In other words, for the most part, you'll see the brand new ads listed first, but there will be some recently updated ads in the mix. The most aggressive sellers will come back frequently to renew their ads and bump them up to the top of the list, but most people don't bother.
Here's another way to look at it: The oldest ads always sit at the bottom. So you don't need to worry about browsing through the entire list to find a new ad.
Regards,
Jonathan Atkinson
www.ballroomdancers.com