Have you actually seen the official terms on this, or just heard it through the grapevine? I haven't come across this personally, but these kinds of referral schemes do pop up in tourism industries - Dubai's definitely competitive about visitor numbers. The legitimacy depends entirely on where the offer's coming from; if it's through official Dubai tourism channels or a verified hospitality partner, it could be real, but if you're seeing it on random social media posts or sketchy sites, massive red flag. Even if genuine, £600 sounds generous enough that I'd want to see exactly what hoops you'd have to jump through - like how many visitors, how long they stay, what they book, etc.