To promote the site to collectors, put together a video of etopps Classics, especially the etopps Classic Baseball events, showing each card for about 10 to 15 seconds. Along with the photograph of the card, include an audio snippet that's famous with that player.
Here are a few simple examples:
Audio of Announcer: "I Cannot Believe What I Just Saw."
Vin Scully: "Behind The Bag!"
Phil Rizzuto giving a play-by-play of Munson tagging someone at the plate
For football, since there are so many action shots you can tie a couple of players together for a play such as Pat Sumerall describing Mike Singletary blitzing Phil Simms.
Even if etopps does not take the lead on this, give us an archive of audio snippets and run a contest for the best montage video to promote the site for youtube.
It doesn't have to be Classics. It can be current players in the middle of a fielding or hitting situation.
Bottom line: make the cards come alive.