When I see it, it is not the original poster that is "tagging" the threads. Like the example I gave, yes it is a for sale add but that isn't the OP tagging it and if I recall, it didn't need bumped at that time. Notice the time stamps, TFL for sale forum does not need 2 bumps in a 24hr period. Sale volume is low, stuff just doesn't move down to the bottom very fast.
I have also seen it in non-sale adds.
"Once you quit hearing sir and ma'am, the rest is soon to follow." - Cormack McCarthy
"Feed me, or feed me to something. I just want to be part of the food chain." -Al Bundy