This study recommends nine statistical indicators as tools for analyzing release, read, and relay behaviors in frst rounds of selective spirals (FRoSS) of online communication. With city brand (city name) as the selecting factor, seven Chinese cities as the selections, and 75971 postings crawled in 27 months between 2015 and 2017 from www.toutiao.com as example data, we illustrated the calculation, application, interpretation of the proposed indicators for theory building or practical decision making. The study distinguishes per-act selections, i.e., release, read per release, and relay per read, from cumulative selections, i.e., release, read, relay, and relay per release. We combined features of correlation coeffcient r and r2 to produce directional r2. We also developed indicators to quantify selectivity and contribution. The results show that agenda setting by senders through traditional media might be giving way to agenda negotiation between releasers, readers, and relayers through online communication. Releasers may dominate the negation, as in our data releasers contributed 66% of the content distribution at the conclusion of the frst round, while the readers and relayers contributed the remaining 34%. Unlike traditional senders who set the agenda by monopolizing the channels of mass communication, the online releasers negotiated the agenda with the receivers and relayers and exerted larger in?uence by being more selective than the other two role groups.