Starting in 2018, Billboard will change the way it counts streaming music for its charts. Right now, the way it works for the Billboard Hot 100 songs chart is that there are two tiers for streaming music: on demand (where you can select what you listen to) and programmed (think Pandora). On demand listening is given a greater weight than programmed. But next year, the company will add another tier. Paid subscription services (such as Apple Music and the paid tiers of services like Spotify) will have more weight than purely ad-supported listening and unpaid tiers of subscription streaming services.