Vimeo: Promo Code
Unlike YouTube's massive audience, Vimeo's is a smaller, niche community of film enthusiasts. It's not nearly as large — it gets roughly 70 million unique visitors each month — but its modest size creates an intimate and fully engaged community. It's a network of people who are genuinely interested in film quality, too, so you know your work is being seen by people who will appreciate it.
Plus, you're more likely to get constructive criticism in the comments section. (On YouTube, even a video of a baby owl stretching its wings for the first time is guaranteed to launch a string of off-topic, mean and flat-out racist comments.)