Ownership of customer relations

Many hosters make their money servicing consumers in a low margin business. Many of them have a business brand like Cohaesio vs. Surftown or Schlund&Partner vs. 1&1.

I’m not sure how realistic a scenario would be where a hoster would give up customer relations by only selling delivery platform services. In fact 1&1 has grown from a direct marketing company to the biggest hosting company in the world. The point I’m making here is that maybe this is a different type of service provider which might not be the classic hoster. I wonder what kind of partner is such a SaaS provider?