Given a less convenient departure station
I recently booked a first class ticket from Lisbon to Porto. It wasn't until I received the ticket that I realized it's not from the main Lisbon station. This is less convenient for me. Also, if I was departing from the main station, as a first class ticket holder I could use the first class lounge. The booking engine only asks for departure city, not a specific station. I won't use Rail Ninja next time.