There are two major parts associated with search engine optimization, or SEO: on-site and off-site SEO. When we are referring to on-site SEO, we are talking about actions such as adding titles, meta descriptions and keywords to content. Off-site SEO is all about using links and social signals to get people onto your website. Here are a few important things that you should know about link building.

1. Velocity of Links

Google is going to pay a lot of attention to the link growth that your site is displaying. It is important to Google how many links are being added each week, month and year. If you have a site that is a few years old, Google has plenty of evidence for what your baseline of link growth is. If that link growth is suddenly spiking after many months, then Google will investigate further.

The discrepancy can be explained by some outside event, but if that is not possible, Google will attempt to see whether you are trying to cheat the system. If you are caught cheating the system, it could be a death knell for your site. Even on new sites, Google can use evidence from sites of a similar age, or in a similar category, to understand what your link velocity should be.

2. Trajectory of Links

We already know that Google looks at how many links are being added. But did you know they also look at the rate of link growth? If you are going through an up-down cycle of link growth and this cycle is repeating, Google takes it as a sign of something suspicious. Sometimes events like site launches or PR moves can trigger these up and down waves. But if there is no explanation, you could get a penalty on your site.

3. Distribution of Anchor Text

A lot of sites make the mistake of stuffing keywords as part of the anchor text they are using for links. When the anchor text appears natural to Google, there is no issue. But if you have a site that is reusing the same two or three words for every anchor text, it appears like spam. And that can result in a heavy penalty, even if everything else on your site is in order.

And that is why site owners have to stop targeting keywords with homepage SEO. Instead, it is a much better idea to look at the link profile and anchor text distribution of the top five sites in your category. You can use a tool like Open Site Explorer to identify the anchor text used by competing sites in order to ensure your site has a similar profile.

We advise that 50 percent of your links should come from major brand names and related URLs. The other 50 percent can come from keyword rich anchor text, with each keyword being limited to 40 percent at the most. If you are planning to use multiple keywords, and those are only half of your anchor text, you are in good shape.