1. They don't force you to sit inside, rather allow you to go to the loo or just for a little walk.

It might be true for the seminar that you attended but historically there's limitation of how often people are allowed to go to the toilet.

All the participants benefitted a lot from this program.

That's a silly statement. You very likely don't have access to metrics to know whether it's true.

P.S - They don't force you to advertise their courses, they just ask you to make a difference in someone else's life whom you care about. Also, we signed up for the advance courses ourselves.

They tell people that they can say "No" but they do exert psychological pressure on people to advertise the seminar.

Landmark quite often pretends that the care about inviting friends&relatives for a graduate party and then treat that graduate party as a sales event.