Any maker is lucky to have a single product in his/her lifetime succeed. Most freelancers only work on a single project at a time, and the success of those projects is mostly in the hand of the client who is responsible for the specs, marketing, integration, etc. Employees of good companies have the opportunity to work in an environment where a process has been put into place of creating, marketing, selling and distributing multiple successful products and input from all levels is integrated and contributes to the future success of the products.
Put another way: the median contribution of an employee at a great company is much higher than the median contribution of a maker or freelancer. The average contribution is up for discussion, but it is skewed towards the very few outlandishly successful.
"Any maker is lucky to have a single product in his/her lifetime succeed."
Not nowadays any more, you can make several iPhone apps, web sites, etc. The products don't necessarily create millions, but they may be good investements.
For example, I make a crappy iPhone app in two days -> publish -> app makes $1000 -> good investment for me. For me, success=good investments of my time & money.
Put another way: the median contribution of an employee at a great company is much higher than the median contribution of a maker or freelancer. The average contribution is up for discussion, but it is skewed towards the very few outlandishly successful.