They'd already experienced the downsides of an invite-based rollout for a closed network, thanks to Orkut in the mid-2000s.
It flopped in English-speaking countries because invites were so limited when people first started talking about it, but became a success in Brazil and India as the buzz built a little later there, by which time it had become easier to get and share invites.
They then compounded the error by force-partitioning their users between the existing service and an invite-only New Orkut, with no easy way to communicate between the two.
That disaster was still playing out when Wave launched, so at least some part of Google ought to have been aware of the importance of network effects for a product of this type.
It flopped in English-speaking countries because invites were so limited when people first started talking about it, but became a success in Brazil and India as the buzz built a little later there, by which time it had become easier to get and share invites.
They then compounded the error by force-partitioning their users between the existing service and an invite-only New Orkut, with no easy way to communicate between the two.
That disaster was still playing out when Wave launched, so at least some part of Google ought to have been aware of the importance of network effects for a product of this type.