One of the challenges of entering the VoIP consumer space is to simply sign up users; so how do you match up the fact that Skype has over 100 million registered users (even if only max 7 million, and climbing, are on Skype at any given time)?

A lot of posts yesterday about Gizmo Project’s newly announced “All Calls Free” program whereby registered GizmoProject users can make free calls from GizmoProject to either VoIP or PSTN phones, provided both parties are registered GizmoProject users. At the right is the resulting right click menu for individual contacts.

The genius in this program is the attempt to drive market awareness virally by getting all your (PC- and headset-equipped) friends and family to sign up for GizmoProject and experiment with it. You then have the option of calling them at no charge; they can receive the call on either the GizmoProject softphone or their legacy PSTN phones. However as Mark Evans states in his post, “Telco Hell“:

“The idea of free calls will no doubt appeal to the bleeding and leading edge who have no concerns about using software and computers rather than traditional telephones. For the mainstream, the Gizmo Project is probably difficult to grasp.”

Alec Saunders, in his post, Gizmo “Friends and Family” concludes:

“If you primarily call North American numbers, for now Skype is a better offering. It’s really free. It may not always be, since free calling is supposed to be a promotion. If you make lots of calls overseas, depending on where you call, Gizmo may be a better offering (if you can get your friends and family to sign up for it).”

Om Malik, in “Voice Now Nearly Free“, speculates on the business model: ”

“This free voice movement had me thinking – what kind of a loss is acceptable to these companies? Though it is hard to get a straight answer, Jajah officials say they can make up all the losses in premium services such as scheduled conference calling, or other such services.”

The limitation for GizmoProject’s “All Calls Free”, as Mark implies, is that the party initiating the call needs to be using a PC with a headset (or equivalent USB audio device). This highlights the thinking behind Skype’s decision to launch a hardware certification program which has resulted in devices that let a much broader user base of non-geek users effectively “add” Skype to their current phone services. Devices such as VoIPvoice’s Cyberphone and UConnect or Multi-Link’s TeleVoIP Stick.that provide links between traditional telephone keypads and Skype, And, of course, the forthcoming Skype for WiFi phones eliminate the need for a PC.