&gt; - a simple tally of reactions. With an open-ended set of emoji, it&#x27;s a bit silly to tally emoji responses. With 6 options, the tallies are interesting.<p>Slack&#x27;s implementation is worth using to question whether of your speculated problems would actually be significant. It updates the tallies in real-time and requires only a single click to increment the count. Although people could use any emoji, in practice there are only a small percentage which are relevant and people tend to add to previous ones rather than add a random new one.<p>&gt; - advertising. These six actions are a known quantity and can be baked into their advertising and display algorithms at every level. Using emoji, you&#x27;d have to build some kind of emoji-emotion-algorithm which classifies the use of all emoji in real time to a small set of factors for use in the algorithm<p>If an advertiser was trying to do this, they&#x27;d have to do all of that work either way – the only difference is the size of the lookup table. I think they&#x27;d be more worried about trying to gauge the target of the reaction – e.g. if I post something about politics and you use the angry reaction, it&#x27;s much harder for a machine to tell whether you disagreed with me or were directing some righteous indignation at the subject of the story and that&#x27;s the most valuable bit of info to know for deciding which candidate or party&#x27;s ad to show.