"You Take My Self, You Take My Self Control"

Here at work one of the biggest problems that we have, and one of the biggest problems I think all companies have in this day and age is internet abuse. Normally I'd just accept it as a cost of doing business, but problems arise when the person abusing internet privileges is someone who wants to continue on and eventually become a bigwig at a company. If you're happy being stuck at an entry level position, it's not nearly as big of a deal. You'll be there forever, and as long as you work hard, you'll end up with a check at the end of the week and a job for quite some time. However, when you're trying to move beyond that to a lower, middle, or eventually upper management position, you can't do it.
Anyway, we have someone here who wants to make a career of this job. I've talked with them about not using the internet, especially not using message boards, which are wonderful tools. I've had some great debates on message boards, but the upshot of them is that you spend a lot more time there than on the average site because you're engaged in an ongoing conversation(s) with people. When everybody at work knows that you spend acres of time reading message boards and you're trying to move up, that's a problem.
My question is how much money is an incentive to stop reading message boards? Of course, it's a long run situation, but the difference between what this person is making and what they could be making if this would be fixed (of course there are other things, but this is one of the big issues people have had with them) is astonishing. A simple back of the calc program look at salary spread shows me that at his current salary and taking into account nominal standard of life raises, they'd probably make $1.25 million over the course of a 40 year career. However, that's compared with $4 million over that same career if they'd buckle down and decide to stop the internet abuse. Is $2.75 million not incentive enough? That seems like a pretty big incentive to me, even if the feds take half of that.