Such pre-prod environments are often required for solutions where Sitecore is tightly integrated with either e-commerce or enterprise search, for example, where it is not feasible to have a preview functionality covered by the Preview mode which runs in Authoring environment. Such scenarios call for a dedicated environment that is as close to production as possible, has all integration hooked up. Another positive aspect of such a configuration is being able to send a link to preview.yourcompany.com/page.aspx to whoever gives the final GO.
Similar approached were discussed in the following blog posts a while back here and here, and now in 7.2 you have a standard way of handling this scenario.
The following changes have been introduced as a part of this new feature:
Figure 1 the new preview publishing targets field on a workflow state
Figure 2 the new preview publishing target checkbox on a publishing target
Figure 3 the content editor warning for an item in a workflow state with preview publishing targets
These changes allow for early controlled publishes to specific targets.
The benefits here are that the publish target restrictions are workflow based. Additionally, it is customary to have an auto-publish action on the final state. With the above configuration that is still possible but we may also implement a publish agent that runs nightly, publishing things to QA, or weekly publishing things to Embargo. Embargo could be another securely accessed site available for early access to a restricted set of users.
The dev team would like to give special thanks to Andy Uzick for providing insight on the real world scenarios and use cases.
Good day now.
Sitecore 7.2 Dev Team