Difference Between Xbox One Game Preview and Preview Program
The Xbox One Game Preview Program was announced back at E3 2015. It allows developers to release games to the public in an unfinished state with the understanding that the product will continue to be iterated on once in the hands of the public. Good examples are Ark Survival Evolved, Sheltered and The Long Dark. These products you can buy at any time.
The Xbox One Preview program is a select group of Xbox One users who Microsoft uses to help bug test and give feedback on updates such at the NXOE update that just happened this past fall. This program is invite only and even then Microsoft will select people that match their needs.
FAQ: Xbox One Preview Program: http://support.xbox.com/en-US/xbox-one/system/xbox-update-preview-faq
Other Videos By XBLA Fans
Other Statistics
Ark: Survival Evolved Statistics For XBLA Fans
At present, XBLA Fans has 628,555 views spread across 24 videos for Ark: Survival Evolved, with approximately 1 hour of Ark: Survival Evolved video on his channel. This is less than 0.13% of the total video content that XBLA Fans has uploaded to YouTube.