Slimmer seats on some planes may bring bigger profits for airlines like United. But they will likely mean less comfort for passengers.

It was just a small hop from self check-out at the grocery store to self check-in at the airport. Now you can even self-tag your bags and self-board the plane. What's next?

In recent years, sales at airports and other travel venues have risen far more quickly than at regular stores for many chains, prompting luxury retailers to focus on the travel market.