Probably it was some kind of marketing activity, I can’t say for sure. It’s up to you if you want to use it or not, but be sure that it is real Hitbtc. There are a lot of Hitbtc clone/phishing sites on the Internet. You can read more about it here https://medium.com/mycrypto/dissecting-a-hitbtc-phishing-site-8e631a6c29a3