Just as a newsbill is an advertisement, not an informational headline, and requires a different approach to a traditional print headline; online headlines must take into account that they will be the primary hook for reader searches. The syntax of online headlines is fundamentally about what will make sense to someone searching and scanning a summary of results… so the initial audience is actually a search bot from Google, or Yahoo! Slurp, not a human being. (Search bots are the pieces of code which are programmed to crawl web pages and help search engines to index content).
There’s a brief article about this topic on the editorsweblog, with the emphasis on SEO (search engine optimisation).
and following from that piece, the Journalism Iconoclast covers the topic in detail:
The New York Times published a good article about making headlines Google-friendly a couple of years ago: