Members get profile pictures and more PM storage and functionality.
Member see no ads on the board.
At the present time while the Straight Dope is making some money from ads subscribers are also greatly appreciated. All bux to the plus side is good news.
It was once believed that potential ad revenue would far exceed subscriptions and would have the added bonus of not requiring customer support, which is an expense of time and money. For example, if it takes an hour of technical time to chase down a glitch in the system because someone’s $7.48 didn’t register, you’ve not really made any money and have in fact come out on the negative side of that transaction.
Anything that you do that throws bux our way is helpful. If you choose to subscribe that is helpful. If you click on ads, that is also useful.