[pittendrigh]

You get to make a choice. You can ignore the embedded multi-media links.

Birding is a burgeoning outdoor sport. Fishing and hunting are in demographic decline but birding is exploding. Many birders are competitive. They make lists and feel triumphant if they see more birds today than you did (I don't react to birding that way but many do).

You don't have to see a bird to have it count on your daily list. Birding works on an honor system. If you heard a Pileated Woodpecker but didn't see it you still get to put it on your list. All birders accept this.

At birding conferences there are ALWAYS lectures on how to identify birds by sound (by their songs). Bird sound books are popular. Bird song books are the first category I can think of that are all switching over to electronic only. A paperback could come with a packaged DVD. Publishers tried that 20 years ago. It's expensive and nobody likes it.

Bird song books are starting to be made (like What the Robin Knows) with embedded audio. People like it. That's what they are buying. Short audio clips are small and can be embedded in the ebub, as you download it. Even so their support is spotty. What the Robin Knows plays audio on the Google version but not the Kindle version. All that will change. No multi-media ebooks will be like 8-track tapes soon.

Audio combined with video (required for technical how-to-do-it genres) is too big to store on a phone. Google, Kindle, Mobi or whatever don't support streaming well. If at all. But it's coming. Whether you like it or not.

In the meantime I do it with HTML and server-side scripting. My customers love it. Try teaching someone how to build a boat with words only. You cannot. You can make a passable stab at it by including still images (jpegs). But the combination of video AND WORDS blows that out of the water.