I have a book I think would make a good e-book—it's fiction but with lots of relevant (historical and political) links to videos, archival photos, cultural analysis. Is it a good idea to market this to agents and editors as a potential e-book? Or would that seem gimmicky? Also, would it make it seem less literary?
An e-book original is, unfortunately, still perceived as a last resort for a book. Since, to my knowledge, e-book publishers operate on a no-advance payment structure (with higher royalties most of the time, to make up for that) pitching your project as a "good e-book" is like telling agents they might never make a dime on it. So, not an ideal foot to put forward! Instead, pitch the book based on all its general merit; then, in a separate paragraph, argue that your topic lends itself to unique opportunities for digital engagement in an e-book edition, which would be an asset to the overall publication if creatively constructed. Every print book is going to have an e-book edition as well, so this way your pitch sounds like there's a bonus aspect.