When you exhibit your work, most venues don’t let you make holes, use pins, or even tape. They do allow you to use glue dots because they don’t do any damage to the walls.
You can make your own and save $ with this glue called Tack-It Over and Over. I save the wax paper from the backs of stickers just for this reason. To make them, I drop small dots of glue onto the shiny side of the paper, and space them out a little. Then, I leave them in an out of the way spot for a couple of days to dry.
After they dry, I cover them with another piece of waxy sticker paper (shiny side facing the dots), and use them like I would the pre-made ones. A bottle of the Tack-It glue was $2.50, and I’ve been using the same bottle for over 3 years.