I've just asked our Webgal Holly to pop up samples of three emailed circulation marketing campaigns I received recently for three different trade magazines. You can steal ideas and spot what NOT to do from each. Check these samples out at:
http://www.marketingsherpa1.com/magazines/sherpa_mag.html

My input:

- None of them has the order form incorporated in the email itself, although all are HTML campaigns and I've been assured this is "not hard to do."

- Although I'm a fan of BrandWeek magazine, their campaign and landing page are definitely the lamest. The copywriter must assume that everyone already knows the benefits of subscribing and what the mag is all about because there's no true descriptive copy. The solitary hotlinked response is well below the fold.

Also for reasons known only to their Webmaster, the landing page requires visitors click on yet another link to actually get to the order form. You guys know you lose at least 10% of your visitors with each click they have to make, right?

- The MediaPost campaign creative is fine (this is just one in a series of almost a ten they sent over time to convert free trials into paids) BUT they omit one critical fact in the email -- when your old MediaPost subscription expired. We get several copies here at the office, and didn't actually realize one had run out, so we never responded to any of the emailed offers. It's the first item noted on the campaign landing page however.

- The Sales & Marketing Management magazine email campaign was superlative. A nice fat "act now!" button at the very top, several hotlinks to click on, solid descriptive copy in readable letter-style black and white typeface.... Then the landing page killed it. Why would you send out a lovely colorful email and then have people click to a stiff form with no sales copy, that uses completely different colors? It feels like the hotlink was wrong - this can't be the right place!

Next time, let your email creative team take over the graphic design for your landing page as well.