They didn't cherry pick the cheapest place - they responded to a local government tender to provide a dark fibre network using the local authorities as anchor tenants. There was also central government funding from the LFFN fund to help make the project viable.

By using the council as an anchor tenant they were able to run dark fibre to the council buildings and at the same time lay dark fibre for use by business and residents. CityFibre then act as a wholesaler to ISPs that sell the services to the public.

According to Greg Mesch CF can offer cheaper prices because they don't have any existing copper products. OR can't undercut their existing copper based products.

In reply to a post by Woolwich:

That Zen link doesn't show me a price but I'm 99% sure their 900/900 on CF is £40. Vodafone's is £45. What happened to Zen being expensive!

I got the CF Zendesk price from - https://www.zen.co.uk/broadband/ultrafast-fibre-broa...