In particular, the Google web spam team is currently waging a PR war on sites that rely on unnatural links and other ‘manipulative’ tactics (and handing out severe penalties if it detects them). And that’s on top of many algorithms already designed to look for other manipulative tactics (like keyword stuffing or boilerplate spun text across pages).
Now let's look at a trickier example—one where the root keyword arguably does a good job describing what we are selling. Say I own an online jewelry store that sells all types of jewelry. To rank highly for the keyword jewelry would probably be at the top of my search engine marketing goals. And yet this would probably not be a profitable keyword that will drive relevant traffic to my site. That is because, from an organic SEO perspective, you are unlikely to rank highly for this term unless you are a huge, highly authoritative site—or lucky enough to be Jewelry.com, knowing that Google rewards keywords that match website addresses.
Another example when the “nofollow" attribute can come handy are widget links. If you are using a third party's widget to enrich the experience of your site and engage users, check if it contains any links that you did not intend to place on your site along with the widget. Some widgets may add links to your site which are not your editorial choice and contain anchor text that you as a webmaster may not control. If removing such unwanted links from the widget is not possible, you can always disable them with “nofollow" attribute. If you create a widget for functionality or content that you provide, make sure to include the nofollow on links in the default code snippet.
Great article. Do you use some tools that generate the best-ranking keywords, and if so, which ones? Also, once you hire someone to optimize your website, does it mean that you don’t have to change it ever again? I’m asking because I see that a lot of SEO techniques are outdated and not only do they become useless, they can even harm you. Is that true?