Yes, I think it is a viable option, particularly if you use Amazon’s 70% royalty Kindle option as then there is no cost upfront. (Actually I’ve put my first novel up). I have heard of several people who have sold so well this way that they then get taken up by a traditional publisher. I am hoping that will happen for me, and even if it doesn’t -already I’ve had a few sales which is very exciting.
You do have be very sure you have edited your manuscript thoroughly first. As well as getting friends to read mine, I also got them to pass it on to people they knew who didn’t know me at all, so that I could get honest opinions!