So, I've been searching a lot of threads under the Nexus 5 category and I haven't found one that answers a question I have so I'm starting a new post. Why is it that the Nexus 5 when bought from the Google Play Store works on Sprint, T-Mobile, and AT&T? I thought it was impossible for GSM and CDMA to co-exist on the same phone but the Nexus 5 does it w/o batting an eyelash? So why aren't all phones sold in the Google Play Store built with the same feature?