Marketplace "bumping"

I've noticed recently that the marketplace listings have succumbed to constant "bumping" which brings the same few listings to the top, while perforce making genuinely new listings disappear down the list.

Guessing it's done by "editing" a listing without actually changing anything in the listing?
(I filter out Reverb offers so I don't think it's anything happening there)

I guess it has more to do with constantly notifying users who have a specific module in a watch list, rather than putting one's own ad above others in the list.

Yep, the used market is THAT dead.