This very small button is 3/4" in circumference and was likely used as promotional material. It is a round blue button with the IBM logo at the top and "1 MEG" at the bottom. In between is a 1 MB memory chip. The back is sticky, silver colored, and has a serrated edge.

The date is a complete guess. The IBM logo is the one adopted in 1972 and the 1 MB chip was first produced in 1987. So this was likely produced some time after the chip wasn't in commercial use anymore.