Hi -
The way they work their promos, if you hit the # of stays, they automatically top up your account to 6000 points, thus generating a free night cert.
At any time, if you hit 6000 points, the system automatically sends out a cert and zeroes out your point balance.
Last year, I hit 6000 points on the first night of their summer promo. I got a cert, point balance zeroed out. Then after two more stays (total three during the promo period), my point balance got topped up to 6000 points. Another cert was generated and my point balance zeroed out again.
They get a lot of my "in one night, out the next AM business".