I've been a Linn's subscriber since the late 1960s, and from the beginning saved articles of interest as "tear sheets". I finally switched to the digital edition about 8-10 years ago, and began to save digital "tear sheets". I consider Linn's to be the best of the independent (non-Society affiliated) publications at the present, although the ASDA does publish some excellent materials and runs a close second.
Linn's business model appears to be based on four pillars:
(1) Advertising, to sustain the business side,
(2) Delivery of news about events in the philatelic community, and the various post office/postal systems, emphasizing the United states and Canada, but with good covers of other countries,
(3) Information about new stamp issues from around the world,
(4) General information about different areas of philatelic/postal history interest through their feature articles and regular series of columns by experienced and expert writers.
In my view, Linn's sees itself primarily as a "news" resource more than a "reference" resource. Perhaps half of their their published contents are time sensitive or ephemeral in nature - their value diminishes over time.
The exception to this view is found in their feature articles, and the regular columns. These writers regularly present material about how to collect stamps, the philately of a dozen or more countries or geographic regions, specialized topics, with something for everyone. Some have been preparing their column for years; a few have probably been writing their column for Linn's for more years than the current editorial staff have worked at Linn's. While I may not collect the things many write about, I enjoy reading what they have prepared because it is interesting, entertaining, and broadens my general knowledge about this hobby which I love.
Their digital edition in its original format brings these feature to the collector easily and conveniently - and without the large stacks of print issues I used to have and which caused such dissatisfaction from my spouse. I can archive them on my computer, and can generally return to most articles when the need arises. [I've developed my own indexing system.

]
They do a fair job of making their content available on their website for the long haul, but it is not always easy to find. In my mind, the lack of ability to easily locate and read articles from their on-going series is a negative. They could really use a better facility that would allow the reader to quickly find and read all of the columns prepared by a particular author: John Hotchner, Tony Wawrukiewicz, Ken Lawrence, Matthew Healey, Chad Snee, etc. Searches by author's names do not always bring up useful lists.
I have also observed that some columns are not presented on-line in their original or complete form. This can be annoying when a writer mentioned something in passing and one can not find it in the online version.
Is $29.99 too much for a digital edition subscription? Not in my book. It's no more than the cost of a nice stamp or cover for one's collection, or five visits to Starbucks. Support Linn's, they do as much for our hobby as anyone.
Mike