GoDaddy is the largest domain name registrar, so it’s only natural that they offer web hosting to go with it.
There are currently no GoDaddy coupons or GoDaddy discounts other than what is currently offered on their website.
GoDaddy is known as a great place to register a domain name, even though I prefer NameCheap, and they are equally know had a bad place to host a website. Mix in that they force you to use a caching plugin which will cause all sorts of headaches for you.
It is a good general practice to not have your domain names registered where you host your website.