IHG Rewards Club has a new promotion for 1,000 bonus points for a stay within 60 days after you sign up for it.
Edit: This offer maybe only for one stay and not for unlimited number of stays.
You can earn this 1,000 bonus points unlimited number of times during the 60 day period.
Note that this offer is combinable with all the other IHG Rewards Club promotions that you can find here.
You should sign up for this promotion when you have your next IHG coming up to maximize the 60-day promotional period. The expiry date of this promotion is unclear.
IHG Rewards Club had a similar promotion previously. This is a great bonus offer for those that have number of stays coming up within the 60-day period, as you can earn it unlimited number of times.