You must register here http://www.bestwestern.com/summer
Register now and stay 3 separate times at any Best Western® branded hotel between June 17th and August 19th, 2012, and earn a free night voucher* redeemable at over 4,100 hotels worldwide This promotion is limited to residents of USA, Canada, Bahamas and US Virgin Islands.
Aeroplan members, if you don’t want to earn a free night, you can earn 2,000 miles per stay, up to 3 days for a total of 6,000 miles. Personally I’d take the free room but if you’re close to a redemption level this is a good way to top off.
June 17 – Aug 19, doesn’t give you much time to make your stays, but you could also check-in / check-out every other day on a 6 night stay to get a free night.
You can use the voucher through January 31, 2013.