I am building an SMS text to win competition to publish in the UK and have been looking at Fortumo.com for the premium sms API. Has anyone here had any experience with them, I have not been able to find any reviews on google etc. Alterntively any one reccomend a supplier?

Looking for entrants to sms to a shared short code with keyword and answer (A, B or C) and then have that POST or GET my url for processing and return a message billed at premium rate. Dont want to spend a lot on set up costs so prefer a revenue share model. Must have an API that can be called using PHP without too much bother