Google is certainly the biggest platform that people build on. How many businesses would die if their business had a catastrophic SEO failure tomorrow? The poi

Google is certainly the biggest platform that people build on. How many businesses would die if their business had a catastrophic SEO failure tomorrow? The point of platforms is that they make things easier, which is something that most businesses desperately need. You just have make sure that you understand the risks-- but they are oftentimes worth it. Zynga would never have built what they've built without Facebook. Yelp would be a tiny fraction of what it is without Google. Quickbooks would have a rough time without Windows. That said, picking a really early platform has more risks (read: Twitter). Picking a platform run by a company that isn't really experienced being a platform (your Ventrilo example and, again, Twitter) has more risks. But punting platforms as a concept is just dumb. 85% of venture-backed startups are dead in 3 years. More than that, likely, in the bootstrapped world. You need every advantage you can get.