Companies often want to know what technologies their competitors are using. It may be as general as are they using open source or Microsoft web servers, or as specific as what version of forum software are they on? Or, they may want to know which websites use a particular technology, to dig out a vendor's client list.
One great way of finding this information is to look through website source code for tell-tale signs. References to AWS for Amazon Web Services, for example. Calls to specific ad servers, or other code references specific to a particular technology. Unfortunately, such searches are not easy - Google does not allow for direct HTML searches.
Instead, there are services such as BuiltWith, which we have covered before. For a small fee, BuiltWith provides a list of hundreds or thousands of websites that use a particular technology. Thus we find for example that columbiahouse.com uses Magento.
Or, similarly, here are some of Omniture's clients:
As with any search engine, the initial query may need refining, but the potential of NerdyData is clear. It can be a great tool for finding out what technology your competitors are using, and conversely, the client list of a web technology company.