Is that 1.1M unique twitter users? If so, wow.
No, many are duplicates. Think of it like exposures in normal marketing terms. A web banner may get 1 million exposures, but many will be repeats. However, repeats are often very value - people are more likely to click something after seeing it a couple times.
If she's smart, she'll realize that the entire campaign to retweet this message is made possible only by Bitcoin - thus the campaign is a demonstration of the technology and should intrinsically convey why it's important and interesting.