I think this might be account specific but google currently have an offer running that if have never used google pay and you 'invite' them, as soon as they spend something (could be a 30p pack of gum), you both get 10 worth of store credit - upto 100 - I've already had 80 that I spend on films and apps.

Worth checking play if you've never used it - also because my wife has another offer where she got another 10 for her first five purchases....