Lufthansa Surprise and the art of blind-booking
A few years ago I used Lastminute.com's "top secret hotel" option on a trip to Munich - an option that allows you to book hotels at bargain rates as long as you are ready to accept one condition: that the identity of the hotel won't be revealed until after the booking. You are given some details of the hotel type, services and approximate location, but nothing else.
The Munich experience turned out to be quite satisfactory, it was a nice room at the Hilton, and it is now, precisely from Munich (and Frankfurt) that Lufthansa is rolling out a similar service: Lufthansa Surprise.
You choose by theme (nature, sun & sand, culture, etc.) and Lufthansa will give you a number of possibilities (for example, the "sun & sand" option can end up taking you to cities such as Barcelona, Nice or Malta), you would then complete the booking process as normal, shown the prices, etc...but without knowing the final destination until you have pressed the "book" button.
This is an interesting initiative when it comes to travel curation and inspiration, a stage of the travel planning and booking process that somehow airlines are starting to pay more attention to (see for example what Air France, Emirates, S7 and Iberia are doing in the field of travel inspiration)
Lufthansa's subsidiary Eurowings has its own equivalent programme, Eurowings "Blind Booking", that works along the same lines (with the interesting refinement, though, that you can pay €5 extra to avoid specific destinations!)