Note that this is for the "life" of the device so we're likely only talking a few years for most people.

I agree, but there's little downside when it's free. If you use this and they cut it off a few years later, you've lost nothing.

You have lost something if :

- you paid more for the plan than you otherwise would have - went through "early adopter" pains as three rolled out - weaved Skype into your business/personal processes, and now have to pay for it, whereas you may have taken another route if the offer were not available - based financial arrangements around having it available for free - factor in the time for finding/learning something new and converting your contacts to it if you now abandon skype.