Thinking about the kind of client that owns a little-medium firm of products (wine, furniture appliances, bling-bling...) and wants an interactive catalogue to distribute among his clientes, I am trying to find reasons to add the option "epub3".
If I were to offer interactivity as the selling point, I think I'd be better off making a tiny website with a CMS linked to a database.
If I were to offer a really well-shaped document, with everything neatly and properly set that would be seen always the same way without trouble, I'd offer a PDF.
If I were to sell him a gorgeous interactive catalogue with bells and whistles in a tablet, I'd even try a budget for Adobe DPS.
But, What would I *gain* as a product by taking the epub3 road today? Any ideas of any advantage for this kind of enterprise? The kind of advantage that make you say 'hey, wait a minute, here it is something rally worthwhile'?