If one donates to Soulseek( on their official website a certain amount), they get privileges. If you have privileges, then your downloads will be queued ahead of other users (basically you side step a long queue for downloading).

I use Nicotine, and when I open the client, it shows for a couple of seconds at the bottom/tray No active Soulseek privileges before vanishing. That's the only clue.

In practise, my downloads usually go through normally. The 5 days I had privileges I honestly didn't notice much difference. Some users have an automated script that crawls one's folder whenever you download from them, so as long as one has decent amount of shares, it's alright. (I only have shared 40 odd gigs but it's decent enough).