Q&A services are all the rage right now, with sites like Quora and formspring adding tons of new users and piling up the archives of content. And now Quora is taking a huge leap forward in engaging content by adding the ability to embed YouTube videos inside of their Q&A pages.

The web went through a bit of a Q&A craze several years ago with Yahoo Answers and several similar products–Google even had a failed attempt at getting a questions service off the ground. But maybe what was missing with those services was the kind of rich, engaging content that video can provide?

Quora built its solid user base by appealing to the tech elite. And it’s a closed system, one that you need to sign up for an account to use–which should help keep out the kind of garbage content Yahoo Answers has become known for.

But the addition of video is huge. Surely I don’t need to preach to this audience about the power of video to convey thoughts and emotions in a way that is vastly superior to simple text.

Consider the sample Question thrown out by Mark Bodnick, who is part of the Quora product marketing team. He points to the recent submission of “What’s are the best storytelling songs?” as a perfect example of how video can make the Q&A experience richer:

A video of a song embedded as an answer to that question is a far more engaging response than someone typing the name of a song and the artist. With video, readers can actually experience each suggested answer

It’s also another sign of video’s pending world domination. It’s showing up everywhere. Bloggers are now vlogging. E-commerce sites are adding product videos. There will always be plenty of products and services on the web that are not video-based, but soon enough, they’ll all at least be using video in some way: for promotion, for internal communication, for richer content offerings, or as a core product.

What do you think? Are you a fan of Q&A services? And if so, how do you think video will impact their usefulness and popularity?