I’ve already corrected Nielsio on this once. BTC is a commodity. Bitcoin is a proof-of-work system. It’s useful because it proves that you’ve spent resources generating BTC. This means someone can charge for otherwise relatively free actions such as signing up to a website, posting on a forum or sending an email. This forces spammers to incur higher costs, making spam less profitable and reducing the overall amount.
Read a long explanation I posted here if you’re interested: Don't buy Bitcoins (video) - #41 by bitcoin2cash
Please, stop spreading the myth that BTC isn’t a commodity. That’s simply false.