Even so, giving up percentage is like giving blood. I don't know of any founder who would ever willingly part with 60% of the company - particularly if it's doing well! The only people who give up 60% of a company are the poor guys on dragon's den...
This, and also competent VC's (and Heroku's VCs are top-notch) don't want much more than a third of the company in a single round, as it makes it far too difficult for the company to raise capital that it may need in later rounds.
Your math is just backwards. You have left them with what's taken away, rather than what they keep. A 1M on 2M pre deal would leave the founders with 66%, not 33%.
