As a writer, my primary motivation is simply that I can't not write. It's baked right in. But the reality is that there is another motivation that writers who are aiming toward publication may or may not be willing to admit. Yes, we all write for ourselves, but the reality is that we also write so that others may read and enjoy our writing. Otherwise, there would be much easier ways to make a living. I already have a full-time job that, while no one would classify it as easy, I'm quite good at and from which I get great satisfaction. And I get a lot less rejection as a teacher than I have as a writer. So when someone says something positive about my writing, it really does mean a lot.
The reason I bring this up is that I sent out my second manuscript to a few beta readers. And I sent my first to those folks too so that they could read from the beginning. One of the readers contacted me partway through the weekend complaining she wasn't getting any work done because she couldn't put the book down. I saw her this morning at work, where she told me that she had finished one book and was halfway through the second. Her response was, to say the least, positive. Another reader said, among other things, that she loved my narrator.
I hate to admit it, but I felt like I was going to pop from excitement when I heard these things. Yes, it's a nice stroke to the ego when people say positive things about my work, but that really isn't the top reason for my elation. It was simply the joy of knowing that I had created something that people responded positively to. That they felt the same enthusiasm for the characters and story that I felt as I was writing it. And that, if these people liked them, other people might too and I could have a chance to actually sell my work and make a living as a writer. That I'm not wasting my time pursuing publication.
So, to quote myself, now to get the darn things published.