This is the whole point. Twitters, diggs, stumbles can automatically follow or not. Unless you have solid content, there is no point in building hordes of links because you cannot build visitor loyalty without good content. http://www.weightloss.com/ has only 900 odd links but was in the first page on Google for an enviable keyword "weight loss" for long times. I think it's the quality of links that matter more than the number.