At the moment it's only used in the discord to get you the 'Dot holder' role and when you want to sign up for events e.g. the keynote in London on Tuesday, as they're only open to Dot holders, but Nothing have plans to add further functionality/features in future e.g. using them for pre-orders, exclusive rewards etc. (we don't know their exact plans or even the extent of them though so plenty of potential for exciting stuff) so they definitely do/will have a use, there's just not much to use it on right now.