Kellogg's and Microsoft teamed up in 1997 to provide discounted Microsoft software and hardware products when consumers mailed in proofs of purchase from Kellogg's cereals:

https://news.microsoft.com/1997/10/28/microso … into-breakfast/

A .PDF of the Kellogg's mailer for 3 1/2 inch floppy discs is attached as well as an image of the floppy that they sent. In order to keep the size of the .PDF down, smaller text borders on the illegible. Demand must have been higher than expected since I received a copy of The Best of Microsoft Entertainment Pack instead of the Microsoft Entertainment Pack Volume IV that was advertised. I always wondered what sort of mailer they had for CD-ROMs (if any). Please post if you have one.