Weighing up the choice between a custom built system and open source? (assuming both are available).
It makes much more business sense to go with the open source version, that way you acquire a version that has grown off the back of failure, they’ve already made all the mistakes.
Building a custom system means it’s you that make all the mistakes and inherently pay for them.
WordPress (the engine behind this very blog) is a great example, by leveraging WordPress you tap into the collective knowledge & failiings of millions of installations.
Just a thought, open source is entirely applicable in business, especially when you realise that you’re buying the failure of millions.