You could but others could see those dashboards (although not your data). You'd probably be best off signing up for a personal account as well.

The way it works at the moment is that all dashboards are visible to everyone you invite to your Corrello account. However, they all get their own copy of each dashboard, which uses their Trello credentials to load the data for them. In this way you don't accidentally share data with people who shouldn't see it by creating a dashboard in Corrello. This was a bit more work for me to build and a little more complex to explain perhaps but felt like the correct behaviour.