I'm aware of what a pyramid scheme is. In the sense that this type of course requires more students (some of whom will also be 1500 hour guys) for each 1500 guy, and then exponentially more students for the next tranche is much like a pyramid scheme - hence why I wrote they're a bit of a pyramid scheme. I suppose I could have written '...a bit like a....' but I didn't think my meaning would be misunderstood.