In regards to "limited advertising" (an optional watermark on your site, and a "Singlelink" watermark in your SEO title), we only add this for our "cloud-hosted" customers that use our free tier.

Just like WordPress & wordpress.com, you can self-host Singlelink with a platform like DigitalOcean or AWS to get instant access to our paid features! (singlelink.co is 100% open-source at the moment, and the only thing we plan to close-source is billing)

I hope I answered your question! Appreciate the comment :)