Non User Initiated Downloads is a term coined by me, Jesse Friedman. It refers to content of a relatively large file size, being unknowingly downloaded by someone on a device, that doesn’t necessarily support unlimited data downloading.
A simple example would be, someone on a mobile phone (who is not paying for or has access to unlimited data) pulling up your site and unknowingly downloading a large infographic. Many large infographics can be over 5 mb just for the graphic file. If your site content isn’t optimized for a mobile device, your user could be downloading all 5 mb of that infographic before they were given the choice.
To make matters worse, maybe that infographic is in a blog post featured on your homepage. Now your user, who is arriving at your homepage, possibly for a specific purpose, is being forced to download this infographic. This eats their available bandwidth, causes your site to load slower and reduces their available monthly data.
A simple solution for this problem would be to use the User Agent to determine the users device type and provide an alternative.
I developed a WordPress Plugin called WP Mobile Detect which makes it very easy for the User Admin (the person maintaining a WordPress powered site) to swap the content in a post or page based on the users device.
Check out this post where I use WP Mobile Detect to swap a 1.5 mb infographic with a small thumbnail and link to the original file on a mobile device. Now when a user arrives on this post through their iPhone, they are essentially prompted to view the infographic, and we are saving them from the unnecessary download.
Now we are creating a User Initiated Download, where the user specifically requests the file to be downloaded. This also optimizes the visual design of the theme and frankly creates an overall better experience for the user.