MailChimp Integration plugin with Pro Sites - different lists for different levels

I just wanted to suggest an improvement for the MailChimp Integration plugin when paired with Pro Sites. It would be great if there was an option to assign users to a different MailChimp mailing list depending on what level of membership they have within Pro Sites.

For instance, I would like to send e-mails to my free users that give them reasons to upgrade to the paid service. But I wouldn't want members who are already paying to see that. And I'd like to be able to send exclusive e-mails to paying members with additional training or bonus stuff.

I don't think it makes sense to lump everyone together onto one list, so this would be a very helpful feature.