To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots. When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.
Thanks for the comment Slava good too see your team is on top of things and happy you liked the post. The website in the case listed was a client who has taken on an agency who was doing lower quality SEO work which was affecting the site such as the huge link network and a strategy which only revolved around mainly head terms. We saw no long tail integration from the old agency's strategy, so we were able to yield great results to begin with. The clients site has 100's of high quality articles which we were able to re optimize and update as noted. Further to this they had a large index of high quality pages to work from. Sure enough the points listed above were key elements to a far wider strategy which could be 100's of points. I just wanted to include some of the biggest wins and easy to implement points.
Although it may have changed slightly since BrightEdge published its report last year, the data still seem to hold true. Organic is simply better for delivering relevant traffic. The only channel that performs better in some capacities is paid search ads, but that is only for conversions, not overall traffic delivery (Paid Search only accounted for 10 percent of overall total traffic).