Adventures in Epublishing: Visibility

I was baffled this week when trying to figure out how my Barnes & Noble sales for the month of December were beating my Amazon sales.  Now I know we're talking small numbers, here, but even small numbers are worth investigating.  This month I've sold 5 ebooks at B&N and only 2 at Amazon.  I am still convinced that Amazon is the king of ebooks and I figure most people with ereaders have Kindles