When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
On April 24, 2012 many started to see that Google has started to penalize companies that are buying links for the purpose of passing off the rank. The Google Update was called Penguin. Since then, there have been several different Penguin/Panda updates rolled out by Google. SEM has, however, nothing to do with link buying and focuses on organic SEO and PPC management. As of October 20, 2014 Google has released three official revisions of their Penguin Update.
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.
Prioritizing clicks refers to display click ads, although advantageous by being ‘simple, fast and inexpensive’ rates for display ads in 2016 is only 0.10 percent in the United States. This means one in a thousand click ads are relevant therefore having little effect. This displays that marketing companies should not just use click ads to evaluate the effectiveness of display advertisements (Whiteside, 2016).
At HubSpot, we talk a lot about inbound marketing as a really effective way to attract, engage, and delight customers online. But we still get a lot of questions from people all around the world about digital marketing. So, we decided to answer them. Click the links below to jump to each question, or keep reading to see how digital marketing is carries out today.