We have noticed that despite the millions of InChIStrings and InChIKeys on ChemSpider they are not being indexed very well. Thanks to some constructive feedback from an interested party from Google (Thanks Simon!) we have revamped our URLs and improved the nature of how structures can be identified by various identifiers as shown below. These are now all valid URLs to identify a molecule and, as people mbed such links in their sites, indexing is more likely to be catalyzed.
We will also submit an updated version of our SiteMap to Google and see if we can catalyze the indexing of the InChIKeys and InChIStrings at least. This will definitely help in making the web more structure searchable.