Here’s a pretty good reason to join the South African Airways frequent flyer program: double miles on most Star Alliance partners.

Double miles through the end of June on Thai (first flight only), All Nippon Airways, and Singapore.

Double miles through the end of July on TAP Air Portugal, Lufthansa, Swiss, bmi British Midland, Spanair, SAS, Air New Zealand, and USAirways.

Interestingly, United isn’t on the list. First account activity earns 2500 bonus miles. And fair warning, discount economy fares only earn 50% of miles, so earn regular full mileage only under this promo.

If you’re flying on participating carriers within the promotion period, and aren’t flying on deeply discounted coach tickets, crediting your flights to the Voyager program may make good sense.

Flyertalk.com discussion is here.