There are quite a few options to sell your ebook without the benefit of an aggregator:
You can create an account and load your book into one of the following websites, these websites charge a commission on the sale of each book. They do not ship your book anywhere and they do not sell your book for you. Your book is available for sale on their website but you need to do the marketeing for your book yoruself, you however will make more money on the sale of each book. There are pros and cons to going this route.
You can create your own website and sell your books. There are shopping carts and software available if you cannot design the website your self.