This offer originally sounded too good to be true - free calls using Voice over IP (VoIP) service Gizmo Project to any landline and mobile (in 60 countries). Well, as the saying goes “if it seems to good to be true, it probably is”, well it certainly isn’t as perfect as originally thought.
I’m not saying that Gizmo Project isn’t a good VoIP service, because it is. Its ability to record calls natively and various other unique functionality makes it often a better choice than Skype or other services. Also it uses the industry-standard SIP system to transmit and receive calls rather than Skype’s proprietary system.

Well, the offer still stands, but basically it means that in order to get the free calls, you have to have registered your actual phone number with Gizmo and be calling someone who has done the same (and uses Gizmo Project regularly).

Still, if you do have friends who use Gizmo Project as well as you, you can now enjoy the benefit of calling them on their landline or mobile for free if they register as well. There is one question raised here, however - if your friend has Gizmo Project anyway, why not call them using that, if they are available?

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EDIT: Just a note to everyone in the UK, we only get landline functionality, not, unfortunately, mobile as well. Mobile calls can still be made at a price in the UK using Gizmo, they’re just not part of the offer.