Youtube, Netflix, Skype, and many other popular sites have one key aspect in common: They were all given an equal playing field and the same opportunity for growth by internet providers.
Net neutrality is the idea that all content on the internet is treated equally. Net neutrality is crucial for the expansion and growth of the internet. Naturally, consumers are increasingly drawn to interesting cutting edge media in the market place of ideas. Net Neutrality plays a vital role and is "closely tied to technological innovation, economic development, and information access." 
If net neutrality is repealed, only major, well-established sites would be accessible in the skewed marketplace. The lack of competition would result in the stunting of innovation and the newest bells and whistles, resulting in consumers becoming saturated with these larger, overly favored sites.
The internet would lose its star quality of being a hub for innovation.
Suppose only established sites and streaming services are made available at faster speeds or are overwhelmingly "pushed" by internet providers. In that case, most startup sites will never perform well in the market place due to a lack of significant funds to afford better service quality, less consumer interest due to high traffic time, etc.
If internet providers were given complete control over which data they can place in the fast lanes and which ones they can discriminate against by placing in the slow lanes, then it is entirely predictable that most startups will be placed in the slow lanes.
In the long run, this is not only harmful to startups but to the internet itself. The internet relies entirely on innovation. Consumers are increasingly drawn to sites that provide them with something different than what they already have. However, if net neutrality is repealed, then only major, well-established sites would be favored, stunting innovations in media and technology.