Online business is different from “offline” business in many respects, but it’s still “business”.
I see fewer head-over-heals, sell-the-farm-and-get-a-web-site mistakes than in the early days of the web, but even 16 years into the life of the web it seems that the majority of people don’t get it.
I started my first online business while I still had a day job. About a year later the company I worked for went bust and I had to fall back on my online income to survive. It was amazing to see how quickly and how vastly my online business improved once I upgraded it in my mind from being a hobby/extra income to being the main and only income. As soon as that switch flipped in my head I was able to find sloppy mistakes on my web sites that I simply hadn’t noticed there before.
It’s purely a mindset. Treat it like a serious business and it might become one.