MailChimp offers two ways to share blog and website content in your campaigns using RSS. RSS-Driven Campaigns can be set up to go out daily, weekly, or monthly, and automatically populate your campaign layout with the last batch of items from your RSS feed. Pretty cool right?
Update: See the revised version 2 of Shopify RSS feed for mailchimp.
One common problem Shopify users have with the rss feed is that the images don't always appear in the email. This is not really a huge problem and there's some simple steps you can take to fix it without having to revert to apps. Now if the mere thought of touching code is going to make your head explode than I'd suggest you stick with am app and read no further.
Soon (because, you know I gotta work!) I'll show you some options, along with some code that you'll be free to use on your path to rss nirvana. Such code is already in place firing off plenty of happy Mailchimp campaigns around the world so trust me when I say it will work.
Basic feed example below: