I think what he's trying to say is this:
The offer was $15 a pop with free shipping if you ordered three. The total would be $45 for a product no one has even tried yet. For someone who believes the deal is going to be amazing but just wants to just give it a try (meaning, they really only need one to try it out), they think they are going to be getting a deal that will vastly outweigh the cost of buying just one at a retailer.
Now on the other hand, when someone goes to make a purchase at NP they will probably be aiming to reach $200 to get free shipping (which nullifies part of the USPLabs Jacked deal). They see that Jacked is now being offered as well. They want to add that to their order to give it a try. They will only add one because they may already be receiving free shipping and are buying other things they already know they will like and because they just want to give it a try.
In the end, they see they could've just waited for it to come out on NP and paid the extra five dollars and only felt the pressure/urge to buy one.
I'm not agreeing either way on this. There is just a lot of psychology at play here. And maybe it is just strong marketing in the way that it compelled people to buy three when they really only wanted one (especially because no one had used it before). Yes, everyone has a choice in life. And people could've only bought one during the IC release. He didn't need to buy three. But when you see that the price difference in the end for just one isn't that much money, it kinda makes you feel like you were tricked by marketing.
Nahm sayin?