"26.9% of Romney's 150,000 newest followers had fewer than two followers. For other accounts of similar size, only 9.6% of new followers had fewer than two followers themselves. The median number of followers for Romney's new followers was five, whereas the median for the comparison group was 27. This represents a stark and statistically significant difference. If you are a statistics nerd, like us, you might want to know that the p-value on this was 0.0000. For the rest of the world, this means that there is, essentially, a 0% chance that the underlying characteristics of Romney's followers are actually the same as the comparison users."
Phantom followers have a way of haunting campaigns.