Preview pages don't draw you in. Give us ten or more pages in sequence so we can decide whether we want to pay to read more.
At the moment, you've made a comic and there is no real impetus for us to pay to read it, as we have no idea of what to expect.
This isn't rocket science. You have no track record, you are just a newbie who has made a comic. You can't sell it online based on sketches and random pages. If you truly believe in it (as I think you do), give us something to get our teeth into, to make us want more!
I love comics, but I have not had any evidence that I would love yours. Give me some.