As someone who had a Gnip subscription for years I think "invite only" is close to a fair characterization.
It took huge amounts of effort to get them to return our inquiries. Given the huge amount of money we ended up spending that seemed ridiculous.
But I guess that just got us ready for the whole "everyone must move to Gnip 2.0, but no we won't merge the multiple pull requests to make our official client work with our new API"[1] thing. Wow, that was fun...
I think the post was quite clear that it meant "behaves like it is invite only", as others have explained. I have to say, if your job is improving how Twitter looks to developers you are IMHO not doing a very good job of it right now, a lot of your replies appear quite tone-deaf to me.
I appreciate semantics and nuance, and often get called a pedant, but you seem to be missing the argument being made. It's not technically 'invite-only' though it in practice, it is 'invite-only.' This looks like a product management shortcoming that seems all too prevalent at Twitter HQ. I say this as someone who was on Twitter in early '08, but quit late'10. I still believe in Twitter's value, which I thought was obvious, then couldn't understand the disinterest, and finally surprised it caught on with the US public. The company really has a long way to go in product management WRT user experience and developer ecosystem.
