Linking Text

Anchor text, ie. the text between <a>...</a> in the referrer's content, is less important than before. If overused, it may be considered spamming. However, keyword-rich anchor text still sends a strong relevancy signal in small doses. A description of Google's original algorithm noted:“First, anchors often provide more accurate descriptions of web pages than the pages themselves.”

The anchor text of internal linksprobably has much less weight than the anchor text of links from external sites.

Having “poisonous” anchor text (especially pharmacy keywords) pointed to your site may be a sign of spamming or hacking.

The words around a backlink also help Google determine what that page is about. The link 'title' (the text that appears when you hover over a link) may also be used as a weak relevancy signal.

The text specified by the 'alt' attribute acts as the anchor text for images.

Apparently, Google gives extra love to links from pages that contain your page's keywords in their title (ie. 'experts linking to experts').