This term is not exclusive to the realm of cryptocurrency; however, it does appear frequently in the blockchain space. “Astroturfing” is the practice of promoting a product or service—e.g., an NFT or ICO—without disclosing personal interest.
Celebrities such as Steven Seagal and Floyd Mayweather Jr. have been fined by the U.S. Securities and Exchange Commission in the past for “astroturfing” ICOs.
This means they mentioned the coins on their blogs and resources but failed to disclose that they were getting paid to advertise the product.