However, those who follow thousands of others can miss quite a bit of information unless they frequently look in the Replies section for tweets directed at them.

On the same note, only dedicating 15 minutes per day is usually not enough to keep up with the activity unless you are following a very small list of people. As your list grows, you might want to use another Twitter tool to keep it on your desktop, or keep a browser window open that you can refresh periodically. That way you can take a few seconds to scan the page and catch anything that may be important or of interest to you.