It is possible to inject advertisement into a link using a urlshorter.net tool called "CTO Overlay" It's a small non-intrusive overlay on the destination website to advertise your product or services. 

Here are a few examples:

Original: https://www.lipsum.com
Injected: https://urlctrl.com/lorem

How to create an injected link: 

1. Navigate to https://urlshorter.net sign up and sign in.
2. On the left side menu find and click "CTA Overlay".
3. Now on the right side click the "Create a CTA Overlay" button.
4. Choose Overlay style and click the "Create" button.
5. Fill in the details, customize the design, and click the "Create" button. You should see the message "Overlay has been successfully created."
6. On the left side menu find and click "Dashboard".
7. Find an input field saying "Paste a long link" and paste the link you want to inject.
8. Find and click the options icon near the shorten button.
9. At the redirect option choose your created CTA Overlay.
10. Click the "Shorten" button.
11. Your injected link should appear.

PDF guide with images available here: https://theurl.zip/pdf