I wasn't sure if this should go in the transportation or scam forum.
I recently purchased an open jaw flight to Europe for this summer. The online agency I booked through has a 24 hour low price guarantee which states "Find a cheaper flight, vacation package, rental car, cruise or activity within 24 hours of booking and we'll refund the difference, plus give you a $50 travel coupon for future travel."
About an hour and a half after booking the price of my itinerary (same flight numbers, same departure and arrivals) went down significantly through the same online agency I booked through. I filled out their application to take advantage of the guarantee. This is where I learned that the guarantee is worthless.
They will only guarantee it if you can prove it was the same "booking code". However, you are unable to see the booking code unless you complete the check out process. So in order to be credited through their 24 hour price guarantee, you actually have to book the flight. At that point you'd have multiple flights and you'd have to cancel one and pay the fee to do so.
I know that the booking code is the same, they know it's the same. I think it's just a scam.