A woman stands near a poster of an Apple's iPhone 5 at a mobile phone shop in Seoul, South Korea, Friday, Dec. 7, 2012. (AP Photo/Lee Jin-man)

Wal-Mart on Friday slashed the price of the iPhone 5c and iPhone 5s for people who buy new contracts or renew their two-year contracts  in stores.

The iPhone 5c, Apple's lower-cost, plastic-backed smartphone dropped to $29 from $49, on AT&T or Verizon. The iPhone 5s got an ever bigger price cut, to $99 from $149, on AT&T, Verizon, Sprint or U.S. Cellular.

Wal-Mart may be hoping that those very-low prices will convince customers on the fence about whether or not to upgrade their iPhones to give in right now. There is plenty of pent-up demand for a new iPhone, given the way that Apple rolls out its phones upgrades, which is to alternate major changes and more incremental releases. Many people opted to skip the iPhone 5s and 5c to wait for a more significant phone upgrade that's expected to come with the next model of the iPhone.

If Apple keeps to its normal schedule, it will launch at least one new model of the iPhone this fall. The prevailing chatter among analysts and tech bloggers is that the next iPhone announcement will actually introduce two models of the phone -- one with a 4.7-inch screen and one with screen that tops 5 inches.

The current iPhone models have 4-inch screens. Pumping up the screen size of the iPhone would be a major departure for Apple, which has been an industry holdout when it comes to screen size. When Apple rolled out the iPhone 5, it emphasized that its smaller screen was ergonomically suited to the human thumb.

Since then, however, the way that we use our smartphones has changed significantly. The rise of streaming video has encouraged smartphone manufacturers to increase screen sizes across the board, and led to the rise of the "phablet" -- the somewhat clunky industry term for the phone-tablet hybrid.

It Apple chooses to finally jump on the trend, it probably has a very big potential audience. Roughly 70 percent of iPhone owners still have models of the iPhone that are at least two years old, AppleInsider reported in March, meaning that there are a lot of people who are probably dying to upgrade.