I may be 70 years old, but I'm still very much alive and kicking (and still a working man), and I still have an interest in, and an opinion on, most subjects. I've been doing surveys on Rewardia (and a number of other sites) for a long while now, but I am getting extremely sick and tired of being asked at the start for gender and age, then immediately being screened out.
OK I accept there are some topics that might be specifically for younger people, but it appears that at least most of the commercially-sponsored surveys have no interest whatsoever in what we oldies think.
I'd be very interested to hear others' thoughts on this.