I would not call them a scam as they may sue you.
https://www.exoclick.com/terms-conditions/
TWO.- PUBLISHER ELIGIBLE WEBSITE(S).
2.1. ExoClick reserves the right to approve or to deny the affiliation of a Publisher at any time. If not approved, Publisher shall not be entitled to the payment of the revenue displayed in its Administration Panel. The following are examples of Publisher´s Website(s) that are not eligible for participation on the ExoClick Network:
– Websites which contain material that infringes the rights of others (including but not limited to copyright and other intellectual property rights) or which promotes copyright piracy.
– Websites with reference to illicit practices or shock human dignity: Contained with pornographic character staging minors(miners); Contents making the apology of voluntary crimes to life, persons the integrity and sexual aggressions; Contents making the apology of the war crimes, crimes against humanity; Contents provoking discrimination, hate or violence towards a person or towards a group of persons at the rate of their origin or of the group they belong to (an ethnic group, a nation, a race or a religion). Any description will be automatically recorded and indicated to proper authorities.
– Websites that participate in or transmit inappropriate newsgroup postings or unsolicited e-mail (spam).
– Websites promoting any type of illegal substance or activity (i.e., how to build a bomb, hacking, ‘phreaking’, etc.)
– Websites with illegal, false or deceptive investment advice.
– Websites that provide incentives of any nature to require or encourage users to click on ad banners (i.e., charity, sweepstakes, etc.).
– Websites that are under construction or incomplete.
– Websites with extremely limited audiences or viewership (less than 50 unique visitors per day).
– Websites that contain any content violating Spanish privacy laws.
– Websites generated through free blogging or free forum platforms.
– Websites with more than 6 ads per page, sites with more than 2 pop- ups and / or pop-unders, sites with more than 1 exit pop up (all ad networks or affiliate programs together).
– Websites presenting no added value to the users.
– Publisher’s Websites and content are at all times compliant with Organic Act 15/1999, of 13 December, on Personal Data Protection, and shall not violate any law, regulation, rule or custom or violate, infringe or misappropriate any person’s or entity’s rights, including without limitation any property or privacy rights, including intellectual property rights, such as copyrights, trademark rights or rights in name or likeness.
2.2. ExoClick regularly checks Publishers Website(s). If ExoClick determines that Publisher’s Website(s) includes any forbidden content, ExoClick may close Publisher’s account without prior notification. In such a case, Publisher shall not be entitled to the payment of the revenue remaining in its Administration Panel.