Has anyone had any success in getting your product in a bookstore?

I create greeting cards for Historically Black Colleges & Universities (HBCUs). They aren’t made in the kitchen, they are manufactured in a printing factory and have embossed/3D covers and pop-ups inside.

I would like to get some cards in a bookstore, especially the HB Community Colleges around the country but I have had ZERO luck in getting any responses. Any suggestions?