Right now "Subscribe" and "Sharing" present in two totally different areas of the UI, top and bottom. "Subscribe" gets lost, and yet its a pretty powerful selling feature to get people to use the calendar in at least some applications. Maybe cluster the Subscribe and Sharing options at the top of the UI where both are prominent.
This idea has been addressed on the new timely web application. Try out during private beta at https://www.time.ly/new.
All plans are FREE during private beta!