To create a broadly-applicable Web resource, content needs to be searchable through services such as Google. In designing Chempedia, one goal was to offer a tool that would work with the grain of the Web by offering a handle though which the full power of tools like Google could be leveraged.
You may have noticed the string of digits separated by dashes assigned to each Chempedia substance (e.g., 8-0401-9986-1421). The format and length of these "Global Substance Identifiers" or GSIDs were chosen deliberately. Although I'll have more to say about GSIDs later, an important goal in their design was to make them searchable through services like Google.
Over at the Chempedia Newsfeed, I've posted an article discussing the recently-started indexing of Chempedia GSIDs by Google, and its significance. To summarize, GSIDs offer a powerful new way to link your own Web content into a larger system of chemical substance information.