I wasn't going to answer this, but decided to after having mentioned him in today's blog post. (http://carbsanity.blogspot.com/2012/04/neat-part-about-moving-more.html for anyone interested)
On the face of things what's there not to like about Mark? By all accounts he's a very nice man and doesn't turn his nose up (quite the contrary I hear) at fans who approach him at events like AHS to introduce themselves. Overall it would be difficult to argue that Mark has not had a positive influence on the whole debate over what constitutes a healthy diet and exercise regime. Especially when others like Cordain don't really address exercise much (I don't have his books, but does he?) and others revered in this community routinely minimize it (ahem ... Gary Taubes). He's a nice looking guy, looks amazing for a man approaching 60 and walks his talk. Surely (as many have stated here), he's also responsible for bringing folks into the fold of a general lifestyle that has benefited them greatly. Mark makes healthy eating cool.
So what if he's not right about every little detail, right? Well, in the comments on my blog Beth cited this piece by Mark: http://www.marksdailyapple.com/case-against-cardio/
I cringed reading it because Mark has a degree in biology wherein presumably he learned that both fats and carbs and proteins are broken down to produce ATP which is the energy currency in all cells. This is such a glaring error. I've encountered so many in the couple of years that I've been reading his "definitive guides" it's not even funny. I find his carb curve notion of >150g carb leading to insidious weight gain to be laughable on its face, and I first read that back when I was still eating VLC 90% of the time. His science is piss poor and I've rarely read something from him that didn't contain at least one glaring error.
I also wondered when I first "stumbled" on his blog if I was the only one to pick up on the blog being a marketing vehicle. I mean really. Daily posts of the sort he makes (linking to his other blog posts for references and almost never to primary sources) are not very time consuming. Sure he doesn't "push" his stuff on anyone, but write enough about the importance of this or that supplement, and have "Sponsor" notes at the bottom of posts, etc., the message is clear. His supplements used to be far more expensive than they are and hats off to Mark for being able to sell a packet of who knows what quality supplements for several times the price of buying generics at CVS or Vitamin Shoppe, but this is his bread and butter ... erm ... butter and butter.
I'll never forget his response to Jimmy Moore about insulin and how it was "all about the buy in" -- http://carbsanity.blogspot.com/2010/12/insulin-wars-ii-mark-sisson.html
Next money maker will be online course to be PB certified in nutrition. This will make him a lot of money for not a lot of work. And if they're lucky, make some money for the PB Certified folks who paid for the class, but not most.
I think when people are helped by others they presume that person is in the business of helping them. When someone makes money helping others -- be it doctors, nurses, teachers, trainers, therapists -- it doesn't negate their motives for doing so, but folks do need to keep perspective and realize that most aren't doing this to help others, they are doing it to make a living. NOTHING wrong with that, and no doubt helping others in the process is gratifying and motivating for them. But it is what it is.
Mark Sisson is the Jillian Michaels of paleo. Different schtick, same day. I envy both for being able to make nice livings off of their passions. But most here probably loathe Jillian for her nasty ACT on Biggest Loser. You do realize it's an act, right? Jillian puts a lot of free stuff out there too folks, and sells stuff like gangbusters on her website. http://www.jillianmichaels.com. Mark is no different, and he's got marketing savvy up the wazoo. He could probably sell ice to an Eskimo and jerky to a Hindu. That makes him both a huge asset and potential liability in all of this.