A quick analysis of recent airfare data confirms a trick you can put to use this summer. How much you save depends on your willingness to endure a longer trip with a little extra fatigue.

The numbers tell the story: Compare airline ticket prices for both non-stop routes and connecting flights because adding a stop (or two) could save up to 50% on airfare. This doesn't always work -- it depends on variables like routes and the size of your departure and destination cities -- but it can save on both domestic and international itineraries.

These are real prices for round-trip flights from Dallas to London in summer.

• Save $116. Purchase 30 to 60 days before departure:

Non-stop: $1,023

One stop: $907

• Save $437. Purchase 21 to 30 days before departure:

Non-stop: $1,435

One stop: $998

• Save $471. Purchase 14 to 21 days before departure:

Non-stop: $1,459

One stop: $988

• Save $855. Purchase 7 to 14 days before departure:

Non-stop: $1,928

One-stop: $1,073

• Save $1,044. Purchase 7 days before departure or less:

Non-stop: $2,053

One stop: $1,009

Why does this happen? Connecting flights/airlines are not really competing with the non-stops, which target high-paying business travelers. Airlines use connecting passengers to fill any empty seats and they entice them with discounted prices of up to 50% off.

Savings are most impressive for procrastinators but those who delay pay higher overall ticket prices. If you shop when most people do - two weeks to a month ahead of time - you can still save plenty, especially if traveling with a group or family.

Bottom line: A little inconvenience could mean a little extra to spend on attractions, souvenir shopping or going out to eat.

FareCompare CEO Rick Seaney is an airline industry insider and top media air travel resource. Follow Rick (@rickseaney) and never overpay for airfare again.

This tip can save you 50% on flights