Our mission is to raise awareness of the teachings and provide humanity with easy access to the writings. We provide the books and writings for free on our website, yet this only reaches a small number of people. While most people look for a book, they go to a bookstore (online or physically).
Bookstores exist to make money, so they only offer books that have value to customers. When someone purchases our books from booksellers, it demonstrates to the bookseller the value of the books and that the public wants them. Gradually, this is encouraging booksellers to have our books available for sale, which in turn exposes the books to more people. If we only sold the books ourselves, they would remain unavailable where most people buy books. (We have the online store primarily to support students who do not have a place to buy the books).
Since our mission is to raise awareness of the teachings, we are focused on finding ways for the books to be become more widely visible in bookstores, libraries, etc. So, from our point of view, it is better to buy the books from Google, Amazon, Apple, etc.
This approach has gradually allowed us to have the books available in fifty countries (see the link below), with more to come.
So, even though the "profit" for us is lower, the benefit to humanity is far greater.