Heathrow Rewards are currently offering 3000 bonus points when you sign up and spend £100 in a single day, before 28 February 2016. The £100 spend in one day is a fairly major downside. The less points-lucrative alternative offer is to sign up without the need for a spend, and get 100 bonus points! While the terms do say the "offer cannot be used in conjunction with any other joining offer", I am pretty sure you will get the 3100 points, plus you may as well sign up for the 100 points using this offer link/promo code - then if you do spend £100 before the deadline, you'll spark the bonus. As you will earn Heathrow Rewards points, which are convertible into Avios, it means you can actually choose to spend them however you want, whether on, for example, Heathrow Airport vouchers or Virgin Flying Club, Etihad Guest, Miles&More or Emirates Skywards miles. Full details are here. Personally I would sign up, bag the bonus and then sit on the 3000 points: double points promos with the airlines come along every now and then.