Content which is unique, well-written, useful, relevant, and linkworthy in nature.
Search engines count links as votes of trust. Furthermore, having a fewer number of high-quality links is more helpful than a high quantity of low-quality links.
There are a variety of ways to define what a quality link is, but the following are characteristics of a high quality link:
- Trusted Source: If a link is from a page or website which seems like it is trustworthy (or from a website with a solid amount of authority and equity), then it is more likely to count more than a link from an obscure, rarely used, and rarely cited website. Trusted sources are usually sites who boast a good link portfolio of their own. See TrustRank [link:] for one example of a way to find highly trusted websites.
- Hard to Get: The harder a link is to acquire, the more likely a search engine will place trust in it. Also, this means a competitor will need to work even harder to gain that link, or to acquire a link of equal or better value.
- Aged: Some search engines may trust links from older resources or links that have existed for a length of time more than they trust brand new links or links from newer resources.
- Co-citation: Pages that link at competing sites which also link to your site make it easy for search engines to understand what community your website belongs to. See Hilltop [link:] for an example of an algorithm which looks for co-citation from expert sources.
- Related: Links from related pages or related websites may count more than links from unrelated sites.
- In Content: Links which are in the content area of a page are typically going to be more likely to be editorial links than links that are not included within the editorial portion of a page.
- Anchor Text: Links with anchor text using descriptive keywords or phrases when pointing to a website are typically more valuable than links using vague phrases such as “click here.”
Note: While appropriate anchor text may also help you rank even better than a link which lacks appropriate anchor text, it is worth noting that for hyper-competitive queries Google is more likely to place weight on a high quality link where the anchor text does not match than trusting low quality links where the anchor text matches.
The actual “search string” a searcher enters into a search engine.
A keyword, or phrase inquiry entered into a search engine or database. A person types in words and the search engine database returns results that matches the user’s query.
Some searchers may refine their search query if they deemed the results as being irrelevant. Some search engines may aim to promote certain verticals or suggest other search queries if they deem other search queries or vertical databases as being relevant to the goals of the searcher.
Query refinement is both a manual and an automated process. If searchers do not find their search results as being relevant they may search again. Search engines may also automatically refine queries using the following techniques:
- Google OneBox: promotes a vertical search database near the top of the search result. For example, if image search is relevant to your search query images may be placed near the top of the search results.
- Spell Correction: offers a did you mean link with the correct spelling near the top of the results.
- Inline Suggest: offers related search results in the search results. Some engines also suggest a variety of related search queries.
Some search toolbars also aim to help searchers auto complete their search queries by offering a list of most popular queries which match the starting letters that a searcher enters into the search box.