Gmail's invite only approach made sense because in 2004 it was absurd for anybody to offer 1GB of free storage. Hotmail offered 200MB I think.

Compared to that, nobody cared about a Facebook ripoff with a different UI and none of the network effects.

I think it was way less than that. Wasn't it like ... 2MB?

No. It was 1 GB:

https://en.wikipedia.org/wiki/History_of_Gmail

"after considering alternatives such as 100 MB, the company finally settled upon 1 GB of space, a figure that was preposterous compared to the 2 to 4 MB that was the standard at the time.[3]"

"On 1 April 2005, exactly one year after the initial release, Gmail increased the mailbox size to 2 GB, advertising it as 2GB plus"

The sample of the news from these times:

https://betanews.com/2005/04/01/gmail-storage-to-reach-2gb-a...

I referred to what Hotmail had at the time.

Yeah, the change to 100 or 200mb came as a desperate attempt later to stop the gmail hemorrhage.

I kind of remember that was something like 10 or 20MB, but yes, was about 2 order of magnitude less.

True. My grandma was in fb early.. She never even knew what Google+ was. Its only a social network if there are ppl on.

Gmail could send and receive emails outside gmail.

FB wasn't restricted within your likely friends group (all students at particular schools were made eligible at the same time).

GMail's time was different, there was a lot less competition among web services back then.

At the time Gmail launched there were a bunch of mail services.

GMail was different in a number of ways.

1. Exponentially more space in a market where single or double digit megabytes was the norm. GMail's original pitch was that you never had to delete an email, and that you could always find them with search.

2. It was one of the first web apps. It was dynamic in a way few sites were then. Asynchronous JavaScript (Ajax) and Web 2.0 were still new concepts.

No, the difference with Gmail is that email doesn't require a network effect to be useful. If I'm the only one on G+, it is pointless. If I'm the only one on Gmail, it's just as useful as if everyone I know is on Gmail.