The success of Uber, Airbnb, Amazon, and many others has created a massive incentive for entrepreneurs to leverage mobile devices and computing horsepower from the cloud to remove friction from many industries.

That’s why it’s so surprising to find products and services that still have not adapted to a mobile-first paradigm. These five hold-outs illustrate just how much more the mobile revolution has to grow.

Email

I subscribe to about two dozen newsletters and blogs. Most of them helpfully recognize the screen size of the device I’m using and render accordingly, but a few do not. Here are a couple of examples that, ironically, cover the technology industry. You’d think that these would be among the first to optimize for mobile readers. Instead, these two have strained my eyes on every mobile device I’ve ever used, from Windows Phone to Android.

https://wpcomwidgets.com/render/

At this point, there’s no reason why these or any other email sent should not reformat for mobile screens.

Indoor Mapping

I saw a Mets game at Citi Field the other night. I found my gate easily enough, but once inside the park, which is less than 10 years old, I struggled to find my seat. If I had been on the road, I could have used several different applications to find my way. Go indoors, though, and you’re mostly dependent on asking for help or hoping that signage is clear enough and available enough to figure it out.

Google makes so much money from its search engine that it can afford the substantial cost of mapping every road and address. Mapping indoor facilities, though, is expensive for companies not called Google/Alphabet, and return can be elusive. Would getting me to my seat faster have resulted in my buying more food or souvenirs? Probably not. Would walking through the mezzanine staring at a map on my phone significantly increase the likelihood that I’d collide with others? You bet. If someone can figure out how to turn more efficient indoor routing into more commerce, indoor maps would thrive.

Updatable Digital Content

These days, just about every brand of consumer software offers updates with new features and security enhancements. So much of the content we consume, however, arrives on our devices never to be updated again. Tidal, the music streaming service, apparently has artists who update tracks on their digital albums, but they’re the exception. I’m surprised more publishers, from video games to children’s novels, don’t follow Tidal’s example.

Medical Records

I had to refresh my insurance information recently for a specialist I see.  Just as I did when I first visited her office seven years ago, I had to fill out a small stack of papers, which later found their way into file cabinets bursting with other patient records. I’m no closer to having access to all my medical records than I was a decade ago. Scanning warehouses of paper and indexing them for search is a significant barrier, but that doesn’t excuse the failure to digitize the records I’ll generate in the future.

Marketing

Mobile marketing spending has increased a lot, but Mary Meeker shows just how much more companies should be spending. It’s not just the amount of media they’re buying (or not). Many also are not spending on the type of mobile media that could improve return on marketing investment. Facebook and Google are powering the surge in mobile marketing for a reason: both are ideal for performance marketing, including user acquisition and direct response. These efforts can make marketing profitable; give a performance marketer a dollar, and she’ll give you more than a dollar back. Theoretically, these budgets should be uncapped as long as they earn a positive return. Yet many marketing teams leverage digital more for reach and frequency, an impressions and awareness-based approach that underutilizes the channel. They may also trap themselves in budgets that they either cannot change or refuse to change.

I’m sure you can think of other domains that have not gotten easier or more productive as a result of mobile. The fact that so many remain unchanged is a big reason why the industry remains exciting, even thrilling. As much as things have changed, there’s a whole lot more change still to come.