That’s the number from the Hotline. They note that, for her, that isn’t really that impressive. Furthermore, this is a primary and general number. As the Romney memo notes, this number is a little bunk. The NYT’s Caucus points out results for Joe Biden, $3m, and Bill Richardson, $6m. They also give us a bit of wisdom:
In the logic of campaign publicity, campaigns are likely to consider it advantageous to announce numbers at the same time as Senator Clinton if they want their relatively low numbers to be overshadowed in the news coverage. Conversely, waiting suggest they may want to attract attention to unexpectedly strong results.