Diamond Giveaway: Am I Missing Something?

Through the Topps Diamond Giveaway site, I continue to receive offers of cards like this:

For one of these:

Clearly I'm behind the game here but not only do I think the diamond die cuts are not particularly appealing to the eye, I'm not about to deal vintage cards like these for shiny new goofiness. What gives?

I will however deal my '73 Terry Forster, '76 Pete Varney, '77 Bruce Kison, '78 Rico Carty or '99 Andres Galaragga if I ever get same year/earlier year offers involving Reds, Tigers or Cubs I need.