If I remember correctly, the forum restricted max number of adverts to 10 per member (all types - sales, swaps, wanted). This was to stop retailers, those members who are serious collectors acting like a retailer, and spam. A normal airsofter would not need to have more than 10 adverts active, likely only having a couple of adverts per week. Each advert lasts 7 days, you can see how long it has been running, if all 10 slots are used you have to wait for one to expire before you can create a new one replacing it. There is no need for a timer, the adverts already have one which shows how many days and hours it has left to run.
The "group" part does seem superfluous.