My husband and I have had this memo magnetic whiteboard basically since we started dating. Initially it hung at his house in the bedroom and we would keep notes on it, pictures, tallies, or to-do lists. It was initially hung with double sided sticky foam on all 4 corners. It stayed in that same spot until after I moved in with him, although it was removed once or twice for painting projects in the room. I think the first time it came off the wall it took some paint and perhaps even some of the drywall coating with it, which didn't make me happy, and obviously the stickiness of several of the foam pads was seriously reduced. After that it likely fell off the wall a couple times, and so when we moved into our current house it never got put back up on the wall.
First I tried to use some string or elastics pinned to the back of the board, and then thumb tacked to the wall. Didn't work. So then I got more creative and went looking for something sturdier. I was initially thinking plain paper clips, but all I could find was those larger paper clips, alligator clips I think they are called. I cut one in half, bent it around to the shape I was looking for, and used epoxy glue to glue the clips onto the back of the board.