Daring Fireball: Title Junk
[...] pick a name (and, for CMS templates, a pattern) that makes sense as the name of a bookmark for that page. Most bookmarking tools — the ones built into web browsers, and bookmarklets for third-party apps — do use the page title as the default bookmark name. Tools that help people tweet links to articles use the page title as the default description. So make titles useful. Write them for humans, not search engine spiders. Putting SEO keywords in the page title (a) doesn’t actually help your page’s rank in search engine indexes, and (b) makes things harder for people trying to tweet a link, bookmark your page, or scan it from a list of currently open windows and tabs in their browser.