Amazon is a great place to order from online. They stand behind their promise if ordered from Amazon and if ordered from a third party, they contact that seller and try to help with the return or exchange of a product.
Have purchased several products there from cell phones to computers. Their have competitive prices and if you buy something you are satisfied, they stick to their return policy.
Most professors ignore you. They will not answer your questions or help in any way which tells me they are there for the money only and do not care about the students.
Too bad there is no way to give one third or less of a star.