As mentioned in the earlier threads, you can do land investing yourself. Heck, everyone on biggerpockets can do real estate with "no money down." It doesn't mean anyone will do it.
I have followed Mark's strategies and bought his toolkit. Did I make money? Yes, I made 1000% return on my first run at it. FYI, the return was hundreds of dollars so its not like california flipping which would be thousands of dollars in return. You know what spurred me to go further... investing in his program... nope that didn't help me at all. Mark Podolsky gave me a phone call and that inspired me to do it. Now, I did get lucky and I haven't done much since I started. I do think I can do a better job but its a personal issue to stop procrastination and push forward with your goals. Too bad, land investing is not one of my goals right now as I continue to look at buy and hold investments.
If you read these forums, a bunch of people have invested in Fortune Builders and other so called "guru" courses but these courses inspired them and now they are making a killing on their investments. It doesn't work out for everyone but with persistent and hard work I think we can all do it :-)