There is a great debate swirling around how topical links must be in order to give you the SEO value you want. Which links pack the most punch and deliver the highest quality for your website? Which links should you pursue and which ones do not really matter?
Site vs. Page—Context Matters
First, it is important to clarify what Google looks at in terms of site versus page. If Google gives more weight to a site than a page, then the overall purpose of the site is more important to link building than the content of a particular page. If the opposite is true, then the content of the page is all-important. This is a consideration that must be addressed, because there may be a particular article in a page that is relevant to your site, even if the overall purpose of the site is not relevant.
The truth is that there are several considerations for any link, and relevance is not the only thing that matters. While the facts surrounding link building are not always clear, there are three things you should consider with any link that will help you decide its importance in your overall link-building plan.
1) Will the link help your readers? First and foremost, content must be user-friendly. If the link has no value to your readers and will not help them, it is not likely that they will ever click on it or that it will provide them benefit if they do.
2) Does the link make sense in the context of the page and site? Assuming all things are equal, finding a site that is relevant to your topic is a plus. If you are a lawyer, you want to link to law sites; if you are a baker, you want to link to food-related sites. The reason that on-topic sites are of more relevance is because more people who might be looking for you are likely to be on those sites, as well as the fact that Google may give more credence to a link generated from an on-topic site. If the page is particularly topical, that may help as well.
3) Can you acquire the link? If you cannot get the site to honor your links, it does not matter how on-topic or off-topic you are; you cannot get value from these links.
Ultimately, building strong, relevant content and linking to articles, websites and pages that support your work is going to earn the best long-term value.