Aw, buck up little camper. There could be a million reasons for the sluggish sales. In either case, we simply do not have the power to jinx ourselves with incidental things like signing up to a website. Besides, you joined three days ago; how many 3-day periods--one day of which was a Sunday--have you gone without sales since July 10?
Seeing that it's CreateSpace, it's logical there would be an initial flush of purchases as friends and people actively interested in the topic snap up the first orders. Perhaps your initial marketing has reached most of the people it can and a renewed effort might be called for. I'm no expert at this; perhaps you could look for suggestions or post a topic in the Self-pub and POD forum. Or maybe it's just "one of those things."