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So, apparently you go to this file on the success community, which has a link to download a SalesforceIQ package. Then follow the steps to Authorize users to connect to SalesforceIQ. That did not fix my problem at all. I thought it was because I have a Custom Domain, but someone who doesn't have a Custom Domain says they are getting that message too. Maybe it's because my Gmail address is not connected to my Salesforce username in any way. I've tweeted them, let's see if they respond.
You have to do ONE MORE STEP than says on this document - go to Connected App OAuth Usage and unblock SalesforceIQ there. Now to test it out.
If you don't use Gmail, you are out of luck.
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