annual plan on eBay that includes 500 Minutes, 500 Texts, 50 MB per month for a cost of $99 a year. That works out to $8.25/month which is a pretty good deal if it meets your needs.
But many people, myself included, are adverse to paying an MVNO for a whole year in advance. Needs change, people move, MVNOs go belly up with alarming frequency and stuff happens. Plus one of greatest advantages of prepaid is not being locked-in to a given mobile provider for a year or years. With number portability, Google Voice and unlocked and "universal" phones that work on all carriers, it's easy to switch providers as needed or whenever a better deal comes along.
Red Pocket apparently recognizes that there's resistance to year long commitments by prepaid users and has come out with a monthly version of the $99 yearly plan. It comes with the same 500 Minutes, 500 Texts, 50 MB per month, but costs $10/30 days. Red Pocket calls it the Essential Plan. Like its yearly counterpart, the Essential Plan is available on your choice of the AT&T network, which Red Pocket calls GSMA for contractual reasons or on the Sprint network, aka CDMAS. GSMA SIMs are $1 for the mini or micro sizes and $2 for the nano. CDMAS SIMs are $9.99, but unless your Sprint phone didn't come with a SIM you don't need one as Sprint SIMs are reusable.
Source Red Pocket Mobile