I just purchased a book through this website. I had a promo code for 31% off so I was excited to get a great deal, but I noticed while at checkout that there was no box to enter a promo code so after checking out I sent them an email explaining the situation and requesting if it would be possible to edit the payment or give me credit. The response I got was this... "Unfortunately items ordered through the textbooksrus.com marketplace are ineligible for discounts."

So they must have several sites linked together and I'm sure this is the excuse to get out of honoring promos. I also didn't get a printable confirmation page after my purchase, although they did email one.