I bought my Cloud 9s in 2013, I use them everyday and they're still in perfect working order. The plates are a bit scratched though, so I wondered whether that was bad for my hair, and Google told me that hair straighteners should be replaced every 3 or 4 years (as apparently the plates can heat unevenly or overheat with age).
I know that might well be a marketing trick to get people to buy new straighteners, and I hate throwing out things that are (seemingly) working perfectly well, but I'm just curious whether people on here replace their straighteners every so often or keep them until they wear out?