I've not read this thread but have received a few mention notifications and I think I know what it's all about.
Last year I sold a shed load of stuff. I listed over 900 different items.
As someone who has my own sub forum I made use of both that and the general sale forum. Sub forums don't get the exposure like the normal sales forum does so to help highlight items listed in there I added a footnote to any sales threads I created in the normal sales forum. That included a brief description and some hyperlinks to threads. Each time I created a new listing I copied and pasted the old footnote and added the new link and removed any completed threads. It only took a minute at most. I also had a list, and still do, of all the items I have for sale along with pricing and links to their individual threads. Although the original threads are now locked, people can still view them and I update the lists as and when items sell. It's been 5+ months and even to this day I sometimes get the odd enquiry and sale to someone who's just come across the list and found something they're after. Or someone who wanted something at the time but didn't have funds or someone deciding that they do want/need item x after all.
Not only did I utilise my sub forum to prevent cluttering and spamming the main sales forum, I also grouped together items into single threads as much as I could. Every item I sold was different but I did not want to flood the forum. I didn't need a separate thread for each individual item. I just grouped similar items together, unloaded pics, listed what they were along with prices. I also kept the number of new listings a day to a reasonable level.
If I didn't have a sub forum I would have still done it the same way. A handful of listings a day with items grouped in lots. Footer with links to my other threads. The only thing missing would be a comprehensive list.
As for bumping. I only bumped a few threads a day whenever I remembered. If I'd bumped every thread then everyone else's threads would be pushed down and that wouldn't have been nice.
There was nothing stopping me from flooding the forum and bumping within guidelines but the sales forum would have been dominated by my threads and it wouldn't have been fair on others.
I tried to be as considerate as possible.