In brief: The iPhone 12 series has not only sold well, but also maintained its value over time better than the iPhone 11 range. Apple is now getting ready to release the iPhone 13 during the usual September launch window, so if you're looking to sell your current iPhone, now may be the best time to do it.

Back in June, the iPhone 12 lineup surpassed 100 million units sold thanks to a new design, 5G connectivity, and the integration of OLED displays across the entire series. The iPhone 11, by comparison, took two additional months to reach the same sales volume despite being launched according to Apple's normal release schedule and without many of the production delays that plagued the iPhone 12 series.

In fact, the iPhone 12 is selling so well that LG is now looking to sell iPhones in its retail stores, much to the dismay of Samsung who is leveraging its partnerships with top South Korean mobile carriers to ensure the iPhone isn't the only option consumers see at Best Shops.

Now that the iPhone 12 has been on the market for several months and we're inching closer to the release of the next iPhone, it's worth looking at how well this generation holds its value over time.

According to SellCell, the iPhone 12 range has lost only 34.5 percent of its value in the first six months since launch. By comparison, the iPhone 11 models lost 43.8 percent of their value over the same period.

The bright spot in the lineup is the standard iPhone 11 model, which lost just a little over 49 percent of its value over the 21 months it's been available. The iPhone 12 family depreciated sharply in the first month after launch, but all models except the iPhone 12 mini gradually recovered some of their value in the subsequent months.

The iPhone 12 mini is an interesting case, since the launch price was only $100 lower than the regular sized iPhone 12. However the mini never found its market, which coupled with the existence of the much cheaper iPhone SE 2, put a serious dent in the demand for the iPhone 12 mini, losing 41 percent of its value in the first six months after launch. The iPhone 12 Pro Max appears to be the most sought-after used phone in the series, losing only 29 percent of its value over the same time period.

Apple reportedly expects the iPhone 13 to sell even better, asking suppliers to increase output through the end of the year by 20 percent. Judging from the rumors and leaks so far, the iPhone 13 will be an incremental upgrade over the iPhone 12, but the Cupertino giant has taken additional measures to ensure this one will land during the normal, mid-to-late September release window.

Another interesting observation in SellCell's report is that Android brand loyalty is falling, particularly among Samsung users. 26 percent of them are contemplating a switch to a different brand, possibly even to the iPhone 13. In any case, if you're looking to sell your used iPhone, right now may be the best time to do so.