If you buy a promotion for your music on SoundCloud, the company or individual promoting your music will not pay you for the streams or plays your music receives as a result of the promotion. Instead, the purpose of the promotion is to help increase the visibility and reach of your music on the platform, in the hopes that it will lead to more streams and plays and potentially help you build a larger fan base.
It’s important to note that buying a promotion is not a guarantee of success, and the effectiveness of the promotion will depend on a variety of factors such as the quality of your music and the target audience of the promotion.