Shopping online is a beautiful thing if you know exactly what you're looking for, but there are drawbacks to buying comics that way. One of the many advantages to shopping at a physical location is the ability to pick up comics and flip through them. Better than any five-page preview, the flip-through gives readers the chance to quickly look at the entire book to see if it catches their interests.
Archaia has launched a YouTube channel that allows online shoppers do that virtually. As you can see when you watch the video for Nate Cosby and Chris Eliopoulos' Cow Boy below, it's a simple concept: A pair of hands picks up an Arachaia book, looks it over, then flips through it, occasionally stopping on pages for a closer inspection. It goes all the way through the book, including the back matter and the back cover.
The project is still in an experimental phase, but the company's already thinking about adding music or possibly narration. Hopefully it will catch on enough not only to encourage Archaia to post its entire catalog, but to nudge other publishers toward doing something similar.
Updated: As a commenter points out below, Fantagraphics has been doing this for a while now and has hundreds of titles available for flipping through.