I don't believe there is anywhere on this site that indicates how many Marriott Reward members are Marriott Rewards Insiders. Also, it is my understanding that this forum was originally launched in 2008.
Have you taken the annual satisfaction survey yet? If not, don't delay. It's a great way to let Marriott know how this site is working out for you, and how they can enhance your website experience.
Good questions. Thanks for posting!
Go to the People tab at the top of this page. Then count the number of pages with MI members. There's 20 on each page, but more pages than I care to go thru since I didn't ask the question. I've been on this site since 2008 so I know it goes back that far, but I was anywhere close to a charter member.