The question is this - is it correct to say something like "I'm planning to sell my books via the Internet". I mean I know it is better to use other preposition but I'd still like to know - is it correct to use precisely this word? The basic meaning is that Internet will be used as the main channel - the tool - for doing something.
A search of the Corpus of Global Web-Based English suggests that the most common preposition in sell [noun] [prep] the Internet is on, as in sell my books on the Internet, though over the Internet and via the Internet are also common.
Both on and via have senses for by means of; the Internet is the tool or method you are using to sell. On the other hand, sell my books through the Internet and sell my books by the Internet are much less popular, even though through and by can also share this meaning.