I am creating a social site hosted by remote server on a service. I am in the early stages fo set-up. The potential for the site to grow is huge but my host does not offer root access, although it does allow multisite. Would be a safe approach to build and run the initial site on the external and as it grows switch to a self hosted server? There will be lots of pics uploaded and downloaded. A few videos. And slew of traffic.
As far as members could be between from 1000 to 100,000 but it will take time to get that high.