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.
Targeting, viewability, brand safety and invalid traffic: Targeting, viewability, brand safety and invalid traffic all are aspects used by marketers to help advocate digital advertising. Cookies are a form of digital advertising, which are tracking tools within desktop devices; causing difficulty, with shortcomings including deletion by web browsers, the inability to sort between multiple users of a device, inaccurate estimates for unique visitors, overstating reach, understanding frequency, problems with ad servers, which cannot distinguish between when cookies have been deleted and when consumers have not previously been exposed to an ad. Due to the inaccuracies influenced by cookies, demographics in the target market are low and vary (Whiteside, 2016). Another element, which is affected within digital marketing, is ‘viewabilty’ or whether the ad was actually seen by the consumer. Many ads are not seen by a consumer and may never reach the right demographic segment. Brand safety is another issue of whether or not the ad was produced in the context of being unethical or having offensive content. Recognizing fraud when an ad is exposed is another challenge marketers face. This relates to invalid traffic as premium sites are more effective at detecting fraudulent traffic, although non-premium sites are more so the problem (Whiteside, 2016).
Blogging website Tumblr first launched ad products on May 29, 2012. Rather than relying on simple banner ads, Tumblr requires advertisers to create a Tumblr blog so the content of those blogs can be featured on the site. In one year, four native ad formats were created on web and mobile, and had more than 100 brands advertising on Tumblr with 500 cumulative sponsored posts.
Two other practical limitations can be seen in the case of digital marketing. One,digital marketing is useful for specific categories of products,meaning only consumer goods can be propagated through digital channels.Industrial goods and pharmaceutical products can not be marketed through digital channels. Secondly, digital marketing disseminates only the information to the prospects most of whom do not have the purchasing authority/power. And hence the reflection of digital marketing into real sales volume is skeptical.
Structured data21 is code that you can add to your sites' pages to describe your content to search engines, so they can better understand what's on your pages. Search engines can use this understanding to display your content in useful (and eye-catching!) ways in search results. That, in turn, can help you attract just the right kind of customers for your business.
The digital marketer usually focuses on a different key performance indicator (KPI) for each channel so they can properly measure the company's performance across each one. A digital marketer who's in charge of SEO, for example, measures their website's "organic traffic" -- of that traffic coming from website visitors who found a page of the business's website via a Google search.