Apple recently announced a trade-in program for off-brand chargers. It offers credit for cheap, third-party chargers. That credit can be used toward an official Apple charger.
This comes after news from China in which a woman was electrocuted when using a faulty charger. This isn’t to say that all third-party chargers are bad, but there are some off-market chargers that have poorly-made components. Here in the US, Apple offers $10 for these chargers. China offers ¥68. Japan offers ¥1,000. Australia offers $14, Canada $11 and European territories offer €10.
Here are more details on the offer.