Twitter touted the recall and memorability of its video ads, citing research it conducted with IPG Media Lab.
The study by Twitter and IPG found that:

Approximately one-half of Twitter users recalled video ads on the social network after viewing just one second.
Video ads were found to be twice as memorable in Twitter?s feed compared with on premium sites, due to content in their feeds being seen as ?personal? and ?self-curated,? as well as relevant to users? interests and ?less intrusive.?
The three-second mark is a key spot for video ads, as recall rose 13 percent between the one-second and three-second marks.
Enticing users to watch the full video allows skippable pre-roll to perform much better than when skipped at some point after five seconds. Branding elements that appear directly above social videos before the ?viewability timer? starts ticking allow for strong branding at low levels of ?time in view? for the video itself.
Providing heavier, early branding can help drive awareness at lower levels of viewability.
Getting to the point by providing the most important information in the ad up front as opposed to spread across the full 15 seconds makes ads much more persuasive.

Twitter global agency research and data strategy lead Heather O?Shea said in a release announcing the study?s results:
While we expected some impact below the industry viewability standard, we were pleased to see that nearly one-half of the audience recalled the ads after only one second in vi...