I think this flippant comment requires some proof to be taken seriously. Its hard to believe digg got to where it was by being repellant to 99% of the population.
That probably works out, actually. Given that the US population is ~300M, Digg getting 1% of that would give them 3M, which is somewhere around their userbase, plus or minus a few million (I don't know their numbers, but Reddit by comparison recently hit something like 8M uniques/month).
Of course, not all 300M US citizens are online, so adjust as necessary. Digg probably got something like 1%-5% of the US online population, which was enough to get it to where it was.