The ability for us to identify who our ideal customers are, with specific needs, interests etc., allowing us to tailor content specifically towards them.
We were able to do this without any additional software! I would say it's not very intuitive at first - we didn't have much training when initially starting up but once we got used to how things worked they became easier than expected. It has been one of the most beneficial tools available within my team so far; being able to filter out people looking just for information rather than products or services.