The New York Post is trying to encourage mobile web visitors to purchase its new eBook. The company is running roadblock ads on its mobile website which stop visitors as they enter the news site and encourage them to click to get more details.

The ad requires a user to either hit cancel to continue to the site or click ok, which then launches the eBook’s listing page.

The Post introduced its line of eBooks last month. The first and only title available so far is called Tricks of the Trade by Ashley Dupre, Eliot Spitzer’s former escort who now works as a sex columnist for the publication. The book includes advice on sex and relationships and is sourced with content from her “Ask Ashley” Post columns.