Cricket Mobile is a Sprint pop-up operator. Cricket buys minutes and megabytes wholesale from Sprint and resells them as Cricket Mobile. It's a good solution for both parties.
Sprint gets a guaranteed income at slightly lower profitability and Cricket gets to sell minutes and megabytes without the hassle of owning and maintaining their own network. Customers who do not wish to or are unable to deal with a major operator get service and the whole market gets a new set of deals. Even better any Sprint phone can work on Cricket Mobile so phone makers don't have to make a new set of carrier specific phones although that can if the want. Pop-up operators are also a good place to sell last years (or older) phone models.
All the major operators are dealing with pop-up operators. Here's a list I've published before showing most of the current crop of pop-up carriers
https://en.wikipedia.org/wiki/List_o...work_operators.
I am a little surprised to read that a Cricket Mobile phone works better than a Sprint phone when the networks are the same. This could be an artifact of the individual phone. I really don't know exactly why.
In summary, if you like Cricket and wish to use it in a new city or elsewhere, check the national Sprint coverage map
http://coverage.sprint.com/IMPACT.jsp?