Swipe ideas from some of the best Facebook ads
There's a lot of psychology and persuasion in this ad, even though it's not immediately apparent.
The opening sentence of this 20i ad starts with the word 'experience', a power word that instantly gets you thinking of how you will be using the service.
The copy is designed so that it's all about 'you' and your experience with the product. There's a £1 incentive that acts as a low-risk incentive to try it out.
Personally, I'd change the image to include someone using the system, rather than a screenshot, but it's effective. So much so, that I now use 20i as my hosting provider.