Instagram Video or Twitter Vine – which is best for marketers?

I know the best thing would be to hit both sites. I'm just trying to get an outlook on what you guys prefer. I prefer Instagram myself. Seems to be more of a following but that could all change.

Vine has a six month head start and now has over 13 million users. Instagram has over 100 million users who (with a simple app update) instantly have video at their fingertips.

Instagram now! They cut Vine deep with the video addition.