Not sure which one you're referring to. Perhaps you mean http://www.amazon.com/Sega-Sonic-Act...dp/B00AG21KGU/ , or http://www.greenmangaming.com/s/ca/e...ultimate-pack/ [slightly cheaper RIGHT NOW with the 20% off code]? Because while those get you Steam keys, it's not technically Steam.
Anyway, we have another thread for non-Humble stuff.