After I purchased a user experience book online and prepared to download the electronic version, I smiled when I saw the Rosenfeld Media download page included the size of the file.
It’s a small, but important detail to provide to your users.
Knowing the file size allows your user to decide whether to download the file on their current Internet connection.
Or wait until later when they have a faster connection.
Don’t make your users suffer through a long download time to get their new purchase.
Provide your users a good experience throughout their online purchase.
Include the size of the file on your download page. And add the type of file (PDF, Word, Excel).
Example: Download your file (PDF: 3.5MB).
With Rosenfeld Media, their purchase process steps had already explained to me I would be downloading a PDF file.