In the terms we are allowed to use images for a certain number of copies. Free images are about 10k copies and paid images are more.
Do copies only refer to print media? For instance if you place an image online on one webpage or in one video that would count as one copy correct? Not 1 copy for each view of the video or each view of the webpage?
Copy count applies to digital/electronic copies as well if you are using the images in an ebook for instance. You can normally monitor how many copies you sell from an ebook. The same goes for a paid video. Indeed, you do not count the page visits if you're using the images to illustrate a website. In this case the number of copies does not apply.
Increase Max Copies (I-EL): Extends our regular Royalty Free / Editorial license to a maximum amount of printed copies of up to 2,500,000 copies. This is an additional license to the rights included within the regular Royalty-Free / Editorial license. Note that the other restrictions still apply.