Just an avid reader. Mostly SF/Fantasy, some hobbies, paranormal, urban fantasy and lighter, fluffier things.
UPDATE — thanks to Grimlock's comment — triangles refer to movement up/down on the chart.
ORIGINAL POST: Anyone know what these colored triangles on Amazon.com mean? (They cannot be clicked and no info shows hovering over them. First noticed next to some books http://Amazon.com/charts .)