Do Links Disallowed In Robot.txt Still Earn Pagerank
Sometimes people don’t want google to index pages for certain reasons and one of the reasons is to prevent there content being displayed in google like there about page or contact page.
Just because the page/link has been disallowed it doesn’t mean google will not know about it. Pagerank can be earnt by any webpage and this is because of the other websites linking to that particular page. If the page has been disallowed in your robots.txt file it doesn’t mean other website owners will not link to it. Pagerank is earnt from other websites linking to a particular page sharing there own pagerank.
If a website has a pagerank 4 and they produce a link to your website some of there pagerank juice will be split with you, the more websites that have pagerank and link to yours will automatically increase your pagerank even if you have specified to google not to index it.
The disallow commend in the robots.txt is only made to prevent content from being indexed and appearing in the search results.