Advertising increases conversions like song saves and artist profile follows, which raises your chances of both triggering the algorithm and the chances of being featured on a Spotify editorial playlist.
If you’re an artist with good save to listener ratios, increasing followers, and bringing traffic onto Spotify, this greatly aides your chances of Spotify featuring your music.
Simply put, ads help bring traffic onto Spotify. If people are leaving whatever platform they're on to enter Spotify, they are significantly more likely to save your song and follow you because they left what they were doing to engage your music.
The cost of ad design, bidding, and management is included in the Spotify Platinum, Spotify Emerald, and Spotify Diamond promotions.