Get a no-contract mobile hot spot that 'pays' you for sharing Wi-Fi

You've heard of FreedomPop, right? It's the Clearwire-powered 4G service that gives you a "free" mobile hot spot and 500MB of data per month, with the option of earning extra by referring friends.

FreedomPop is still in beta, but already it has some interesting competition. Karma offers a Clearwire-powered 4G mobile hot spot with 1GB of free data, with the option of earning extra by referring....strangers.

It works like this: You pay $79 for Karma's compact, 2.1-ounce hot spot, which can share its 4G goodness with up to eight devices. After you activate it, you get 1GB of data that doesn't expire. That's not 1GB per month, mind you, but 1GB, period.

After you blow through that, you'll pay $14 for each additional gigabyte -- a reasonable rate compared with what other carriers charge, though FreedomPop charges $10 per 1GB.

However, and here's where it gets interesting, whenever you fire up your hot spot, it creates an "open and branded" (to you) signal that anyone around you can use. If and when someone does connect to your network, you'll both get 100MB of data. That's the "karma" in question.

And speaking of questions, this raises lots of them. For starters, will people be willing to connect to an unknown network when they've been conditioned to avoid them? And what about security -- for you and for them? Karma addresses the latter issue (among others) on its Help Center page, but I really have to wonder if anyone will trust a hot spot called, say, "Rick's Karma." Another potential wrinkle for some folks: using Karma requires a Facebook account.

The good news is that there's no contract required, and all your accumulated (or paid-for) data rolls over, so you don't have to worry about "expired" data going to waste (which is something I've always hated). Karma alerts you when you're getting low on data and asks you to confirm before charging you for more.

Alas, although Clearwire is available in some 80 cities, metro Detroit isn't one of them. So as with FreedomPop, I'm unable to test-drive the service. Needless to say, you'll want to check coverage for your area before ordering.

On the surface, this looks like some pretty good Karma. Although it would be nice to have at least some guaranteed free data per month, as with FreedomPop, the rates are more than reasonable, and you're not on the hook for yet another two-year agreement.

Your thoughts?