There are two things that are productive in business: serving clients and attracting clients. Everything else is not productive. Many of these tasks don't fall into the category of "counterproductive", but they are not doing anything to grow your business. These non-productive tasks are things like: bookkeeping, filing, reading emails (unless it's an email needed to service a client), shopping for supplies, etc. While these tasks are often necessary, they aren't productive. They aren't going to make you any more money in the long run. So why do freelancers waste their time on such tasks?
It's simple enough to find someone else to do the work for you, but it's more challenging (and arguably more rewarding) when you find a way to do it yourself. I know what your next question is -- there are only 24 hours in a day. How can I make time for these activities when I should really be growing my business? That's a great question.
The best thing for you to do is to review how you spend your day. That means it's time to start tracking your time. How much time do you actually spend working? Are you spending too much time reading blogs (other than this one), browsing social networking sites, etc.? Once you know how your time is spent, you are then able to figure out where to "trim the fat". If you spend over an hour per day on social networking sites, that is probably too much. Try cutting it down to 30 minutes to see if that will allow you more time to work on those non-productive tasks.
Do you have any other ideas for staying productive while running a small shop?