As covered in the Syndication article, Sitemason utilizes common protocols like RSS and iCalendar to make your list tool content available via machine readable feeds. Subscriptions is the reverse of syndication. Instead of publishing content to the world, you're subscribing to content from the outside and bringing it into your own website.
How are Subscriptions Used?
This concept is immensely powerful as most every popular web service provides RSS or ATOM feeds which Sitemason can subscribe to. For example, you may have a YouTube channel where you are constantly publishing content. You aren't publishing videos directly to your Sitemason tools, but you can setup a Subscription to your YouTube ATOM feed and Sitemason will automatically add each YouTube video to your site as a unique item.
Another example of using Subscriptions might be to subscribe to a partner's blog and co-publish their content as your own without having to enter it twice. We have customers who subscribe to hundreds of author feeds they have publishing rights to, and pick and choose which articles are displayed on their site and market that content as their own to their site visitors.
Setting Up Subscriptions
Go to the list tool you plan on adding a Subscription, like your site's blog, and select the Subscriptions tab in the right column.
Select Add from the Subscriptions Action Bar.
If you've entered a valid RSS or ATOM feed, Sitemason will open the Subscription in a new panel with options for managing the incoming content.
You'll want to give your subscription a Name for your reference in the interface. From there, set whether the incoming content should be Approved or set to Pending for your review and later approval. If you aren't 100% confident that all posts to the subscribed RSS feed are appropriate for display on your website, then set this to Pending.
Sitemason list tools also have the option to mark incoming items as Important. This flag is often used to style posts differently or give them some visual weight so the site visitor understands "hey, pay attention, this post is important." An example use would be a university subscribing to an area emergency services feed. If there's an emergency in the area, your students and faculty should know immediately and prominently.
ATOM feeds provide an additional field compared to RSS feeds for the entire description of an article. RSS traditionally only offers a summary of an article, though some services will opt to include the entire body of an article in the RSS summary field. Import description (ATOM feeds only) is an optional setting you can select if you know you want to include the whole body or "description" of an article for a subscribed ATOM feed.
Using Tags for Incoming Subscriptions
A great feature of Sitemason Subscriptions is the option to include Tags on the incoming items. Covered at length in the Tags tutorial, Tags can be any string of text that might describe the content in the feed. From a topic like "gardening", to the author's name, or the organization.
On the Sitemason blog, we subscribe to our president Thomas Conner's personal blog. He uses tags in his blog, and will tag any article he thinks should appear on the sitemason.com blog with "sitemason". We subscribe to his feed using the URL http://www.thomasbconner.com/post/rss?xtags=sitemason so we only get articles tagged with "sitemason".