Existing native advertising networks in the US include TripleLift, Taboola, Outbrain, and Revcontent. These networks provide a platform for advertisers to place native ads that blend with content on websites. They offer various ad formats such as in-feed ads, recommendation widgets, and sponsored content. Other networks like Sharethrough and Bidtellect also specialize in native advertising, focusing on seamless ad integration. Large ad networks like Google's AdSense and Facebook's Audience Network provide native ad options as part of their offerings. These networks help advertisers reach targeted audiences while maintaining a non-intrusive user experience.