If you watch over the past six months, they've actively encouraged third-party publishers so businesses get more invested in twitter, while simultaneously discouraging third-party consumer-focused clients.
I guess advertisers understand publish/subscribe better than social interaction.
It was their tradeoff of reducing usage while users are on LI, while hopefully increasing consumption on their own site from those users.
It's certainly a gamble, since I'd argue that LI was more a source of new twitter users rather than siphoning off views from already loyal twitter users.
The other possible threat in Twitter's head might have been LI bootstrapping their newsfeed off Twitter (which they'd mostly been doing) and then growing it large enough to actively compete with Twitter.
http://thenextweb.com/apps/2012/09/20/ifttt-removes-twitter-...
New plan: post elsewhere (LinkedIn or Buffer) and have it pushed to Twitter, rather than the other way around.
Guess what I do now? Skip the Twitter middleman.
Is the spike because LinkedIn traffic actually spiked, or was it just getting misattributed as Twitter traffic?
Linkedin is vaporware with no revenue.