There are a couple of points about Lufthansa 2-for-1 deal that I think should be made sticky on this board. First very important point is that 2-fo-1 dea includes transatlantic travel on United Airlines. The importance of it is that United Q fares are usually less expensive than Lufthansa itself, plus Lufthansa taxes are about $100 more per person. So, when taking advantage of 2-for-1 deal, flying the entire trip on United(our places that United has direct flights to Germany) may save you a few hundred dollars.

Second tip/clarification is that you can place your reservation on hold for 72 hours without supplying a credit card number, but your fare won't be guaranteed. However, your tickets won't be issued until you supply Lufthansa the VIN number, so you can guarantee the ticket with the credit card, but it won't be charged nor will the tickets be issued until the VIN is supplied. So, once can hold airplane seats for ED for a LONG time ahead, and not pay for the tickets until few weeks before departure(and have the ability to change the itinerary too before the tickets are issued).