1. The "Big Three" Engagement Signals

The Instagram Reels algorithm prioritizes content that generates active, meaningful engagement. While many metrics are tracked, the algorithm places the highest weight on what can be called the "Big Three":

<ol> <li><strong>Watch Time (and Re-watches):</strong> Similar to TikTok, this is paramount. The longer you can hold a viewer's attention, the better. Content that gets watched to the end, and especially content that gets re-watched, is heavily rewarded.</li> <li><strong>Likes:</strong> A "like" is the most basic form of positive feedback. It's a low-friction way for a user to say, "I enjoyed this."</li> <li><strong>Sends (Shares):</strong> This is arguably the most powerful signal of the three. When a user shares a Reel with a friend via direct message, it's a powerful endorsement. It indicates the content was so good, funny, or relatable that it was worth starting a conversation over. The algorithm views a "send" as a high-intent signal of quality.</li> </ol> Your content strategy should be explicitly designed to maximize these three interactions.