Judging by the "huge" (any numbers Posterous?) short term bump, the campaign is successful for its publicity and buzz. But I doubt it will result in long term sustainable draw for Posterous. As the article rightly pointed out, many are also pissed at how it was carried out. I suspect many of those who signed up during the campaign are not actual switchers, but bloggers who created a Posterous account just to test out the import tool. Switchers or non-users whatever, Posterous at least has the number to show to their investors.