Makes perfect sense if it is offered as an "Ads Free" subscription. I offer it as the ablity to turn it off if you don't want it. This is offered to my Supporting Members. All others are stuck with it.
Being a diving community, there are quite a few adds that come up for travel that have great deals. If one of the users is looking to go on a dive vacation or just traveling, then they are able to turn the ads back on to look at the deals that can come up. When done, they simply tick the box to turn it back off.