The majority of comments here are about too long of an invite window, nymwars, and Google Apps. While I appreciate those are important issues for people, acting like they are going to kill Google+ is extremely shortsighted and uninteresting. They are about as much of a factor in Google+'s success as the quality of the concession stands at Fenway to the Red Sox's success.
You have one chance to launch a service like this for a large audience. If you want to do an invite only private beta to get the kinks out then you would probably have to do that under a different name. Once you associate the google brand with it people expect it to work and expect it to work at scale.
Anything less is blowing your first impression. 90 days to wait to try a new service? People are simply not going to wait that long, they might have tried it in the first week but three months is a relatively long period to feel left out, that's a negative first impression. It takes a lot of work to undo a negative first impression.
As for google+ not going to be killed, they did it to wave and plenty of other products that did not attract enough users to be good enough for google, why would google+ be different, especially with a purposefully slowed down launch like this? That only increases the chance.
I don't think Google has done a huge marketing push, yet, considering how big a product this is for them.
They've done little press and haven't bought advertising online or in the real world - something they did for Chrome. They've so far done pretty much the minimum a company of such scale could do for a product this big. It was inevitable that a lot of people would want to join as soon as they heard of Google's plans.
I have a feeling that the marketing push is very much still to come.
sign out of google services and go to google.com
If everyone gets that little arrow, that's a pretty big marketing push...
What huge marketing push? All Google did was post a blog about it and send out some invites.
+1 is a social recommendation and bookmarking service integrated into 3rd party websites and Google's search. It is orthogonal to Google+ (although both Google+ and +1 use the same social graph).
I think they are deliberately meant to be similar.
A couple of levels up I mistakenly thought that the +1 buttons next to my search results were an early buzz effort for Google+. I thought "recommend this page" implied "recommend this page to my friends on Google+". I made that mistake because of the name similarity and the timing of release. If a marketer introduces an ambiguity, I don't think it's the responsibility of the target to disambiguate the message.
I was desperately looking for a way to add posts to my Google+ stream (like a tumble blog) from Firefox and I kept getting ways to +1 stuff, which does end up in Google +1, but hidden away and, grotesquely, with no way to even promote it to a full post.
And then there's these odd news feed like topics you can subscribe to in Plus -- which I guess might work if you're interested in sports or whatever, but I just keep wishing I could use it as a link to the similar-but-different Reader. Incidentally, what happens if you star something in Reader, does it +1 it, Buzz it, or is that another way of socially promoting it?
On a side, yet related, note: did anyone had a google email account in the late 90s? Long before gmail, google had an email service, it was by far the worst email service I've used, full of bugs, many long downtimes and countless other issues.
If web users associate the +1 buttons with Google+ then it is free advertising for Google+.
On any given week, for instance, the floodgates would appear to be randomly open or randomly closed, and I'd send out a small trickle of invites while I could. I would have little indication of when the gates opened and closed, so eventually, I just stopped bothering trying to invite people.
Needless to say, this did not make for a robust graph. Sure, I had my "inner" circles up and running just fine. But whenever I wanted to broadcast something -- in the true sense of that word -- I'd have to go back to Facebook for the bigger friend set.
At the end of the day, you can't toy with people on the inside or outside of a product like this. Users on the inside want their friends inside. And users on the outside want in, to be with their friends. The seemingly capricious, chaotic, and extended open/closed period really caused an inordinate amount of frustration for both groups. Social networking is about one's social network, and when people already had extant social networks, they were extremely anxious to port those networks over.
[Bear in mind that I remain a loyal G+ user and really do believe it's a great product. I just think the extended beta was a bit too extended, and bit too schizophrenic in its betaness.]
 And you can count me as another victim, here. I'm frankly dumbfounded that they'd keep thumbing their noses at the users over this, and I can't believe they either 1) still didn't understand that this would be the first thing folks commented on or 2) don't think it's important. To me it just smacks of unprofessionalism.
The overall number of users in the system isn't something important, it's how many users I know. A network with 10,000 users at Harvard will spread out much faster than one with 10m dotted around the US as it represents a contiguous userbase that is a solid foundation for social interaction.
On Google+ I've got 100+ people who have me in circles, but they are all hardcore geek early adopter net-fiends like myself. Very little of my real friends and family social circle is on Google+... many were interested when I explained it but have since lost interest due to their initial inability to join when the service was the hot new thing.
This was exactly my experience with Google+.
The invite window won't kill G+, but apathy will. About a fifth of my Facebook friends are on it, but only 3 out of a hundred post anything. A successful competitor would need to stand for something other than "well, it's not Facebook."
It may find a niche as a long-form twitter (which is something I can't believe Facebook waited so long to do) but the initial excitement has run its course.
Except for going back to Facebook. :) I got bored with that after about 2 weeks, too.
- APIs (looks like there's significant progress)
- Open-source/open standards/federation (nothing yet)
(I think the second one would really sort of take care of the nymwars and the Google Apps issues, too.)
I've got a ton of feature requests, but those two are what I would consider serious/disruptive.
Regarding the second ("open"), we're taking our usual approach, building on open protocols wherever we can, and creating them when we have to. In this case, Activity Streams and Portable Contacts, with no doubt more to come as we launch new platform features.
As far as federation goes, love it, though one step at a time of course. Let's get the product itself off the ground and stable (today's open signups is a big step toward that) and we'll see what people want to do with it as a platform.
Thanks, Joe! The feedback is always appreciated.