Was once won't ever do that again. I have no real interest in military matters but they did have some books listed I thought I'd like to have so joined. I got my basically free initial shipment but after that they pretty much never had much I was interested in with their monthly flyers. Still I was buying on schedule to complete my agreement in spite of having a hard time finding anything of interest to me.
Well before the end of the period I was to buy whatever number of books my agreement required they started writing nasty letters to me telling me I wasn't buying enough books and sent me a bill demanding payment of some outrageous amount of money to be paid immediately even tho I had over six months more per the agreement to buy the stated number of books. I tried explaining that to them and they would not listen and demanded not that I buy the requisite number of books but that I pay them the outrageous sum of money and that I do it immediately.
I basically told them to stick it where the sun don't shine that in my opinion they had violated the agreement not me as I still had six months to buy the correct number of books and since they not me were in violation I no longer felt a need to comply so I just wrote them off and have had nothing to do with them since.
The amount they wanted was at least three to four times what the real value of books of the type I bought from them was worth at their prices. They have darn few non military books available so unless that's your area of interest you'll not find many to chose from.