The mantra within marketing and R&D departments is that innovation is for delivering differentiation. But the reality is that much of the purpose of innovation is to avoid differentiation. It’s largely about keeping the brand competitive and where it is.
Let me explain, innovation holds that wonderful lure of coming up with something that is better than competitors, but this happens rarely and seldom lasts for long. It’s the cream on the top. The ‘bread and butter’ of innovation is not falling behind. It’s about maintaining features and price levels of rival brands.
In some industries the pace of innovation is frantic. Innovation is therefore constant, but it’s rarely about leap-frogging competitors. You have to run fast just to stand still.
Alternatively not innovating may possibly save you money but even so that would mean changing the position of the brand, you’d be offering something cheaper but below the quality level in the market where your brand was previously. You’d increasingly be differentiated but this is not what most brands want.
The other purpose of innovation is not to cause or avoid differentiation but to find new ways of meeting customer needs.
Marketing, and R&D’s, obsession with differentiation can distract from understanding the purpose of innovation and its proper place within overall marketing strategy. I fear it leads to much unwise and unprofitable innovation.
Marketing Science 
The 1st law of strategy IMHO is “you have to emulate superior advantage”. That means brand-level differences get smaller (or more inconsequential)over time. How Brands Grow goes against my beliefs as a marketer but appeals to me as a scientist. Having said that I do feel it is going to be important to more precisely define the term “differentiation”.