All chats increase your Snapchat score, although not all chats do this equally. Here’s how it works:Sending Snaps -You get a higher score each time you send or open a Snap.Posting Stories - It is possible to increase your score by adding content to your Story.Chats – In order to get higher the score, it works to send messages and not to read or receive chats.Other interactions - Snapchat is also rewarding the streaks, the emojis, and other in-app features, but the algorithm underpinning this process remains unknown.
Otherwise, to be honest, you get more points by sending Snaps and messages, not only passively chatting.