The question is: Who can use Digg, Stubleupon, Delicious, etc.? And if so, how much would you want per link posted, to make it worth your time?
For example: If you posted 1 link on 1 of these sites, how much would that time be worth to you? 10 cents, 50 cents, $1, $5 per link posted?
It's like saying, "I'll give you X amount to move this firewood. What is your time worth?" I don't really know how to make this any more clear but if you have any questions please ask.