Software products don't cost nearly as much as many traditional products, and as a result companies need a lot of users to buy in, in order to make a profit.

Once users start to share their software with one another, it creates a lock-in, where all future users have less and less need to seek an alternative product, as all of theirs friends and colleges are already using the established brand.

This mean that by focusing on how well a product can be shared, instead of how well it could be architected, increases adoption, and therefore leads to defensibility and profits for their creators.