On some level, this is the profitability dream. Engineer something that doesn't cost a lot to run, doesn't need to be changed, and makes a ton of money. Engineers don't like to hear it, because it means less demand for our services, but it's what's best for business.
You can't always drive increased revenue through increased R&D. At this point, substantially everyone who wants a DVD delivery service uses Netflix. As long as someone doesn't come out with a service that makes it significantly easier to rent DVDs over the internet, and as long as attrition caused by the software is very low, any more money spent on Netflix's DVD service is throwing bad money after good.
You can't always drive increased revenue through increased R&D. At this point, substantially everyone who wants a DVD delivery service uses Netflix. As long as someone doesn't come out with a service that makes it significantly easier to rent DVDs over the internet, and as long as attrition caused by the software is very low, any more money spent on Netflix's DVD service is throwing bad money after good.