Indeed, it's hugely to their benefit to be for net neutrality these days. A non-neutral internet would drive up costs for them and/or their customers for the data connection. If it drives up their costs it eats into their profit margin and they either soak it or raise prices. If it raises customer costs as a general increase on broadband cost, then customers have less money to spend on Netflix and other services. If it drives up customer costs because they now have to pay a Netflix prioritization fee, then they might not choose Netflix at all when Mediacom/TWC/Cox/whoever is offering a cheaper streaming media service.