Just a few weeks ago Amazon launched a standalone video subscription service that undercuts Netflix. Now it has mounted its very own YouTube challenger with a new consumer-centric video site, Amazon Video Direct. Amazon Video Direct encapsulates four different distribution models; free videos for Prime members; videos to buy or rent for a one off fee; free ad-supported videos for all Amazon Video customers; and as an add-on subscription through Amazon’s Streaming Partners Program. Content owners will be able to choose any combination of these options to earn royalties. It may look like Amazon is several years late to YouTube’s party, but this announcement follows a trend in which online video sites are not just purely imitating YouTube’s successful (but…