You can now customize or remove the ad units on your Pro paper:

• Go to your Paper Settings / Ad units,
• choose ON in the switch button; 
• click "edit" next to each ad unit to add your own content 

To upload now your own ads, click edit and 

• upload an image, add a url to hyperlink, or
• add HTML code or an iFrame to the ad units on your Pro paper (please respect Paper.li terms and conditions: For security reasons we don't allow animated gifs or java script tags
• Validate your changes and you'll immediately see the results in your paper

Notes to custom html:

• You can modify the height and width of your ad units in the code. We suggest for the 1st ad unit a size of 300x300 and there are two places in the code that values will need to be modified. This is important to note especially if you are adding a video or music player in an ad unit so they display nicely.
• if you are adding custom HTML and not uploading an image, embed the href ( anchor tag) within one cell. 

Do not pass the full html snippet (html,head,body). 

To remove the ad units, you need to switch the button to OFF.