It lost its "momentum" by then. The marketing got "early adopters" excited, the kind that would evangelise a platform, but they were blocked because either they

It lost its "momentum" by then. The marketing got "early adopters" excited, the kind that would evangelise a platform, but they were blocked because either they couldn't get in themselves, or couldn't invite their colleagues. By the time Google realised their mistake and provided access to everyone without an invite, it was far too late.