I'm just making myself aware that in spending time on these sites, I'm taking away from my on-hand cash and moving it to a location that it will be difficult to extract from. So I'm doubling the loss involved in procrastinating.
The loss is just a short term loss with a longer term profit, but being the animals we are, the short term profit overweighs the long term profit, so I tend to keep this in balance.
Also, if I procrastinate a bit, but them work very effectively, I will earn money to cover for what I lost earlier. So it balances out.