Spotify playlist submission services are a common method of exposing new music on a budget. There are also many paid distribution and promotion services.
Promoting your music through blogs, podcasts, and review columns can improve your Spotify exposure.
Many of the direct submission services, that are free, require you to follow the list you’re submitting to in order to unlock the submit form. They are collecting your email address from Spotify, and are likely going to send you marketing email. That’s the price.