Why not order directly from the vendor itself rather than looking for a marketplace? Books can still be sourced from Books-A-Million, Barns & Noble, as well as

Why not order directly from the vendor itself rather than looking for a marketplace? Books can still be sourced from Books-A-Million, Barns & Noble, as well as local shops. If I'm looking for choices for a solution, I'll use a marketplace, but after I find a solution, I'll order straight from the vendor itself