Creating a market is easier than stealing market share
I've done both. The fashion industry is extremely saturated with formal wear brands, yet I launched a suit company in my freshman year of college. Sure my styles and my quality was better than most brands out there, but in all reality, it wasn't a new product. There was no "wow factor." I mean how hard can it be, right? It is a multi-trillion dollar industry, "even if I take 1% of it" (a typical line from the show, Shark Tank) I will be set! Stealing a market share from big companies is one of the hardest things I have done. Why would the newspapers talk about me? I'm not giving them anything exciting. Why would the bloggers talk about your brand when 10 million other brands are offering them free products as well? Good luck getting some sort of social media traction. If I remember correctly, the company Sea-Doo tried launching a motorcycle line after their huge success in the watercraft industry. That move almost pushed them out of business because huge companies like Honda and Yamaha are protecting their territories. You need to have some serious cash on hand when stealing someone's market share, "if you wanna play with the big dogs, you can't piss like a puppy."
Not saying you can't do it. In my experience, it has always been a little tough.
Creating a market however takes a bit longer, BUT in my opinion it's easier. If your product has that "wow factor" it is much easier to market it. With a little bit of social media marketing and contacting bloggers, you should have a decent traction going. When we created America's first bullet-resistant clothing line, everyone wanted to talk about it. We've been featured in so many newspapers, blogs, and even on national television. We created a product and then told people that they needed it. I never did any "market survey" and other textbook terms. Steve Jobs is the perfect example for it. He created the iPhone and told people they wanted it and people did.
So my advice, create something new.