By my count, their page views increased around 75% during the peak days of the viral... not bad, considering that the campaign didn't even have to pay to create it. If that translates into cash in the coffers or new volunteers, it probably won't matter much what people think of the viral several months down the road.
Indeed, looking at a website comparison, Hillary seems to be lagging.
Traffic Rank for barackobama.com: 11,246
Traffic Rank for hillaryclinton.com: 17,417
What matters most is how good a job each of these sites does in harnessing the visitors and turning them into active participants in the campaign. Who's best at that remains to be seen.