Sure, link building is good for business. By having other companies link to a website, it can help prove authority, relevancy and even quality not only for the company it is linking to, but also vice versa.
Link building, however, has some shady practices associated with it over the years. Google has a zero tolerance policy for Link Schemes - in which there are links intended to manipulate Page Rank or a site's ranking in Google search results. But isn't that just search engine optimization? Not really. Here are six questions to ask yourself to determine whether your link-building technique is Google approved.
To answer this question, another question needs to be asked; would you link to this site if Google didn't exist? Does the link provide readers/users/shoppers more information that is relevant to what they are reading? If the answer is no, rethink the link.
Real-World Example: For the unfamiliar, Website Magazine accepts guest articles from industry experts. We receive as many 'spammy' articles (that we reject) as we do high-quality pieces (that we accept). One of the worst we received was actually a terrific, insightful article on Web design which our readers would have loved.
The problem, however, was that buried in the article was a keyword-rich link to "best business credit cards." Obviously this had nothing to do with Web design (not relevant in any way) and had no business in an editorial article. This leads us to the next question.
The same companies that author articles like the one mentioned above try to sneak in keyword-rich anchor text links. Even just one of these irrelevant links can be detrimental for a site's search engine rankings. Keyword-rich anchor text can also be hidden in forum comments or article comments. Site administrators should add a rel="nofollow" attribute to the <a> tag.
Quality is, of course, subjective; Google, however, has offered up some advice as to what defines a quality site and that includes page speed. While it's probably not prudent to check every link's page speed, professionals should make sure links are in working order. So, while there, if the page is obnoxiously slow, they may want to rethink the link.
Chances are, if a site admin has to either manually enter the link or manually approve the link, the link is likely better in quality and relevancy. Of course that's not always the case, but site admins that monitor comment sections of articles, forums or social media posts, are better off. It's also a more valuable link to the person asking for the link.
Buying or selling links that pass PageRank is clearly a big no-no. This, according to Google includes exchanging money for links, or posts that contain links; exchanging goods or services for links; or sending someone a "free" product in exchange for them writing about it and including a link.
Excessive link exchanges ("Link to me and I'll link to you") or partner pages exclusively for the sake of cross-linking, according to Google, can also negatively impact a site's ranking in search results.