Yesterday we noted how AT&T's Microcell femtocell service was already a dubious value proposition given the device, intended to improve in-home cell coverage by routing voice and data calls over broadband, involves users paying AT&T to help ease congestion on local towers. Not only does routing calls over your broadband service result in you eating your minutes, but it also now appears that using 3G at home eats away at your caps. That's absurd, given that both voice and 3G over the device uses the user's bandwidth -- and not precious backhaul resources.

AT&T's been making the rounds trying to give an explanation for why they made the decision to make their Microcell service an even worse value, but the explanations so far aren't making sense.

"3G MicroCell is primarily intended to enhance the voice call quality experience in your home," AT&T's Seth Bloom tells us. "While it can carry mobile data traffic, that’s not the primary solution it provides," he says. "Wi-Fi is the optimal solution for home mobile data use. We encourage people to take advantage of Wi-Fi capabilities - that’s why all of our smartphones include Wi-Fi radios, and usage on Wi-Fi doesn’t count against your mobile data usage bucket."

Yes, as we noted yesterday, customers will probably decide to use their Wi-Fi connection when in the home. That still doesn't explain why AT&T lets the service eat 3G bandwidth caps should users remain on "3G". In that case, the traffic's being routed over the exact same broadband connection as Wi-Fi. Whether users should use 3G over the Microcell in the home when Wi-Fi's available isn't the point. The service still shouldn't be eating your wireless caps just like femtocells shouldn't eat your voice minutes.

Bloom goes on to insist that the Microcell "uses our core wireless network just like a call placed while driving down the highway uses the core wireless network." "The only difference is how that data or call gets there – via a MicroCell connected to a wired broadband connection instead of a cell tower."

Again though, you're not using AT&T's tower or their backhaul, you're using your own already-paid-for bandwidth. AT&T's entire justification for their new low caps and overages is backhaul and tower congestion (though even that's dubious -- simple profit is the more likely motivation) -- and congestion's not an issue here. Sure, there's costs involved, but they're minor compared to the costs of traditional wireless connectivity.

Consider these are users shelling out for a home broadband connection, a wireless 3G and data connection, possibly an added landline connection, the upfront cost of hardware, and an additional $20 if they want unlimited voice that doesn't eat away at their minutes. Just how much are we expecting the average consumer to pay per month for simple, regular-use voice and data connectivity?

Either AT&T's gunning to make an additional few million annually in revenue off of those incapable of differentiating between 3G and Wi-Fi, or they're incapable of getting the Wi-Fi/3G femtocell billing straightened out and don't want to admit it.

Some might think this is all rather nerdy semantics, but these are important questions when exploring how carriers seem to be sucking all the value out of the femtocell with absurd pricing decisions and other penalties -- especially when the femtocell helps the carrier more than it does you.