Just noticed this in Power Editor but previously, the default bid method was for 3 sec views while a 10 sec view bid option was also provided.

The benefits of bidding for a 10 sec view are obviously related to higher retention rates. In a previous post, I have also written about whether you should promote a video post for views or engagement. If you were to bid by engagement, your 3 second costs are again likely to be higher than a views campaign with 3 sec bids. 

This is a welcome change from Facebook as it would now try to auto-optimize and show ads to users likely to watch 10 secs. However, the cost increases might be significant once Facebook starts moving most of brand/pages content to the Explore tab [as announced last week].