Those revenue and cost of revenue figures blend together different things. Their contracts with music distributors (recordings) + statutory rates for music publishers (compositions) = ~70% of the revenue pool from advertisers and subscribers.

However, podcasts work differently, both on the revenue and cost side, and appears to be mixed in. Additionally, Spotify sells optional marketing programs (ads within Spotify, for example) which I assume are included in revenue. So it's hard to draw the right conclusion just from the summary numbers.