Regged in 1996 the domain was once used as a startup and raised $250,000 in 2013.
The .com crowd will love this statement,
Now that we’ve reached a level of maturity and stability in the CRM space, we decided it was finally time to invest in acquiring the .com domain—in part to reconcile that disconnect between calling ourselves Close internally and “Close-dot-I-O” externally.
He also put together a video explaining the decision.
Hat tip to Namepros member ivbran