It depends on the conditions of your employment. If your work is task-driven and it only takes an hour or so each day to meet the objectives, then no harm - no foul. If you will receive no incentives to do more than your minimum daily tasks, it shouldn't matter what you do with the balance of your time.
Of course, this assumes that your employer is cool with this, as well .... every work place is different. It also assumes that you have almost no desire to get further ahead in your chosen career ....
I'm logged onto TB all day, every day .... but I'm not sitting here reading each and every post. I pull up the page every once in a while and give it a quick read-through, then go back to work. I never let any on-line stuff interfere with my work ....
