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.
That second link will still help you because it will pass extra PR to that page. But in terms of anchor text, most of the experiments I’ve seen show that the second link’s anchor text probably doesn’t help. That being said, Google is more sophisticated than when a lot of these came out so they may count both anchors. But to stay on the safe side I recommend adding keywords to navigation links if possible.
For my Adsense plugin which you can get here https://wordpress.org/plugins/adsense-made-easy-best-simple-ad-inserter/ I’ve created a PRO version (https://www.seo101.net/adsense-made-easy-pro/) that is available to those that sign up for my mailing list. It’s not much but it gets me 5 to 6 subscibers a day. And best of all I know exactly what my subscribers are interested in… WordPress and Adsense:)
Search engine spiders can only spider through text. They will use the content on your site to determine what your site is about, which in turn will help to decide how highly your site will be ranked for specific keyword phrases when visitors type them into the search engines. For this reason, keyword research is critical to obtaining natural search engine placement and should be at the top of your list when mapping out your SEO strategy.
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.
Social media is one of the most popular free marketing tools around, and plays a role in driving traffic to your website. Use Facebook, Instagram, and LinkedIn to promote blog posts and other useful pages on your website. This way you can turn your social media audience into website visitors, and draw traffic from their networks if you post shareable content.