Visitors find your site with a search engine. Are you interested in what they were searching for?
Search Engine Referers is a simple module to view the search engine queries used by your visitors. It parses the referer URLs of popular search engines in you access log and extracts the search queries. Currently supported: Google, Yahoo!, Live.com, Yandex.ru, Rambler.ru.
This module is similar to the Search keywords module, but much simpler/lighter (less code, less functions, no install/use of extra database table, no hook_exit() usage, no administration needed, ...). On the other hand, the the Search Engine Referers module depends on the core statistics module, while the Search keywords module has no dependencies.
And, oh... the proper spelling of this module is actually 'Search Engine Referrers', I know, but:
Referer is a common misspelling of the word referrer. It is so common, in fact, that it made it into the official specification of HTTP – the communication protocol of the World Wide Web – and has therefore become the standard industry spelling when discussing HTTP referers.
-- Wikipedia on HTTP referer