I am not a Dante scholar and only read Italian at a very basic level. I've been looking for a basic text to cut my proverbial teeth on, and someone sent me this: http://www.amazon.com/Dante-Alighieris-Inferno-Metaphor-Illustrations/dp/1896584144/ref=sr_1_1?ie=UTF8&qid=1374622062&sr=8-1&keywords=interlinear+dante
I bet his market is pretty small and he'd be very willing to enter into an agreement with Logos; and a digital Dante Lexicon/dictionary shouldn't be too hard to get our hands on. This would be similar to what was done with John Jackson, I imagine, who independently put together the interlinear Iliad that is currently in the Perseus collection.
The great thing about this sort of strategy is, you would pull in many Dante Scholars/students - who, in turn, would be interested in many of Logos' other offerings, particularly the Catholic and even the Classics material. So it would also make sense from a marketing perspective.
It seems to me that the strength of Logos is in it's ability to leverage all its resources to bear on a text, particularly one that is not English. So if Logos is going to expand what is meant by "Classics" I should think expanding in the direction of original language texts will be the most useful and, for them, profitable.
For example, I can pick up a cheap copy of any number of translations of The Divine Comedy; and read them just as well in an actual paper book than on Logos, if not better.
However, it is not nearly as easy to get one's hands on the Italian text; and I cannot think of a better "place" to tackle it than in logos, if Logos had a Dante-focused Dictionary/lexicon.
Now, THAT would be something; and now you'll surely have Dante scholars interested; who, in turn, would probably be drawn into your Verbum offerings, etc.
Just a suggestion 