MENSA Approved! If you were smart, you would use them too.
Then, in return for the certification/approval, the maker of said item could donate x percent of the sales per quarter. Obviously, MENSA would have to watch what they approve and only approve one item from each category (1 bottle of shampoo, 1 pair of jeans, etc...) just to keep the competition up (you know, give the cert/approval to the highest bidder). Personally, I think this would be a great idea.
WARNING: The use of generics and stereotypes here are strictly so no one gets their feelings hurt.
Why do I think this? The average person believes they are not average and are smarter than the average person. They would think, Hey! I am smart! and would be more inclined to buy that product because A) It stood out in their mind and B) It insults all those people that aren't as "smart" as them. I know that is a long shot, but I feel comfortable saying I think it would work just as well (if not better) as the current things they put on products (100% Pure!, Makes your hair shiner better than the rest!, Not tested on animals!) because it would be something new. Now, I don't know how many people in the general public actually know what MENSA is and that could certainly put a damper on this idea if the percentage is quite low, but I think it would be a nice experiment.