I don't think this product entirely competes with travel books.

I think the value is that it makes the decisions for you. You already have your itinerary set in logical/geographic order.

If I'm running through a city for 2 days, I know I can't squeeze in everything. I can either waste time deciding what to do or I can buy this and see something I know will be awesome.

Not to say that there isn't room for other revenue streams or that other revenue streams may be better, but I don't think direct sales should be discounted before a proper test.