My banners vs Aha! banners

As an Aha! administrator, I would like to control who sees banners from Aha! so that they don't blow past my banners thinking they are things from Aha! that they don't really need to read.  I've learned from several of my users that they are not reading the banners that I author because they are so accustomed to just closing the ones that Aha! publishes.  Most of my users are just reviewers, so they don't need to know about features that are really only useful to Contributors and higher.  I'd like most of my users to only see our internal messages delivered via banners.