An argument could be made that authentic autographs are the most important element ever to be added to sports card products. Since the first autographed cards began to appear in the 1990s, signed cards have risen in prominence to the point that they are now the driving force behind many sets across all sports.
Because the card manufacturers take various steps to ensure the authenticity of their autographs, collectors feel more confident in autographed cards than they might for signatures obtained through other channels. They also feel a bond with their favorite athlete because he (or she) actually held and signed that card.
Or they used to anyway. From the beginning of the 21st Century on, an increasing number of autographs included in sports card products have taken the form of signed stickers. Instead of signing batches of cards, athletes sign sheets of stickers, which are then affixed to various cards by the manufacturers.
Initially controversial, sticker autographs have become so commonplace that they now outnumber on-card autographs (also called hard-signed cards) in all sports. Not all collectors have embraced this turn of events, but an understanding of the reasons why card companies use stickers has allowed them to gain more acceptance with each passing year.
Background
As signed cards became a bigger and bigger part of the hobby, it was only natural for card companies to develop more ambitious autograph programs. Eventually the logistics behind printing cards, getting them to dozens of athletes to sign and getting them back in time to meet their intended release dates became too difficult to manage, and the manufacturers were forced to come up with another way of doing things.
The first solution was to release the products with any autographs the companies received in time and insert redemption cards for the rest. Each redemption card entitled the holder to a specific autographed card. The collector simply needed to mail in the redemption (or more recently, enter a code into the company website), and the company would send out the autographed card when they got it back from the athlete.
In theory, it wasn't a bad plan. But problems arose when some sets began to release with redemptions for almost every autographed card on the checklist, angering collectors who had to wait months - or years in some extreme cases - to receive their cards. Faced with mounting negative feedback from consumers, sports card manufacturers turned to stickers.

