How does X define the look-alike audience quality when expanding reach through follower look-alike targeting?

X defines the look-alike audience quality primarily based on the 'seed' audience quality and the degree of similarity between the seed audience and the expanded look-alike audience. 'Follower look-alike targeting' means finding new users who share characteristics with the followers of a specific account (the seed audience). The seed audience quality is determined by factors like the seed audience's engagement rate, their relevance to the brand or campaign, and the overall activity level of the followers. A seed audience consisting of highly engaged and relevant followers will generally result in a higher-quality look-alike audience. X's algorithm also assesses the similarity between the seed audience and potential look-alike users, considering factors like interests, demographics, and behaviors on the platform. A higher degree of similarity indicates a better match and a higher-quality look-alike audience. X uses these factors to generate look-alike audiences that are more likely to be interested in the advertised product or service, improving campaign performance.