We built a consumer facing app using <x>app.com domain and it's been successful and has grown quite a bit. A few business owners have asked us for an API access to our backend and we already have a few paying clients.

We're in the processing of negotiating for the <x>.com domain. When we get it, we need to decide if we keep <x>.com domain for b2b and <x>app.com separate for b2c only or if we combine them all under the same domain.

Wondering if HN community has any thoughts on which approach would be the best? The advantages of combining is to increase the new domain's authority and traffic right away by redirecting existing traffic. The disadvantages is we need to make sure we get navigation right, etc. Are there any examples of startups doing both b2c/b2b that get it right?