Very odd
? First I am guessing that this was only included in the factory sets or other complete set boxes. It seems to me that what they are doing is if you had sent for the certificate (with $5) before the end of 1998. They (Topps) would send you an exchange certificate that could be redeamed in late 2001. They probably estimated that a full set would be worth close to $65 after 3 years. So they are saying for $5 you get a "certificate" (voucher, coupon) that guarantees that you will get $65 for your 1998 Bowman Football set after about 2.5 years.
Also note it is just for series one (cards 1-220) cards from series two or an update set would not be accepted? Sounds like one of the ways they ended up getting some cards for their "buyback" program.
I collect: Baseball, Football, Hockey, Mostly Vintage pre1980, My Homie teams - Washington/Baltimore Teams Senators (Twins, Rangers), Expos/Nationals, Redskins, Capitals, Bullets/Wizards - HOFers - Non-sport (mostly TV shows and movies).
My Trade List is very much a work in progress
CaptKirk42s Trading Card Blog Curly W Cards Strive For '65 YouTube klandersen42