In the earliest days of web retailing, simply having an image for each SKU online was a big deal. Expectations evolved quickly, and now multiple images, image zoom, and color swatching are now must-haves in many categories.
The next step will be video: consumers will expect to see a specific video for each product. Video showing the product moving, in use, with narration.
SKU-level video will require a huge amount of effort for retailers, but should significantly increase conversion rates and decrease return rates.
Vat19 sells "curiously awesome products" . These are under-50$ novelties, high-tech desk toys, etc. Vat19 offers video descriptions for almost every SKU they sell. Funny, edgy, useful videos that show you exactly how the gadget looks and what it does. Videos made by Vat19 themselves.
I'd wager that these videos are essential to selling their unusual products, and that's why they're working to get video for each SKU.
Video won't matter in all categories, but will rapidly become essential for online retailers selling clothing, gadgets toys, and vacation travel.