Hello Craig,  You are correct on the Media Mail rules.  Each post
office has taken its own path on the "rules" to the extent that one
of the local post offices here refused to send a video tape of
a football game two years ago because it had advertising in the
broadcast.  Additionally, they have taken the attitude that if
a video tape has previews of other video tapes those are advertising.
These are extreme measures and may not be universally enforced.

You did not mention the alternative USPS printed bound matter.  This
is entirely suitable for magazine mailings but limited to fifteen
pounds.  This class of mail does not have restrictions on advertising
content but materials must be permanently bound such as by staples
used in magazines.  The maximum cost of this service is $9.50 for
15 pounds shipping to a "zone 8" address.  This usually works out
good if the shipment does not require multiple packages.

http://www.usps.com/send/waystosendmail/senditwithintheus/boundprintedmatter.htm
Bound Printed Matter

I do read your postings even if I spend a lot of time on the sidelines
these days.  Retirement money being what it is, I have found it
necessary to drop memberships in MBSI and AMICA as of last year.

Regards,
Don Shenbarger