Again, I want to make it clear I do not mean this as criticizm. I think your site is great, as well as the work you have done.
But quite obviously there is a draw toward historic players/seasons. EA put legendary players in the game this year, and they have been incorporated with other versions. Also, there are people here and on other sites that are looking to play entire past seasons/franchises. Rosters have been built for every decade, 70's-2000's, basically since the AFL/NFL merger. Since your site boasts having info on 20,000 players, it seems like a logical place one would go to find historic info.
.. anyway, just one man's opinion. Again, congrats on your accomplishments, and good success to you and anyone working or associated with your site.