The Disallow instructions on Twitter’s robot.txt file locked their content out of search engine result pages and made the platform of little to no use in generating SEO links from tweets. Further, Google Plus added a tremendous amount of content from Goolge’s social network to SERPS. They look to be getting ready to give actual link juice from Google Plus posts in the near future. The direct link value for those seeking Twitter SEO value was almost zero.
However, Twitter recently stopped using Disallow for pages that are the product of searches on the website. The problem is Google makes it clear it does not value this type of “content.” They even ask webmasters to to specify in their robots.txt file that such pages should not be crawled, as they do not produce new, unique content. However, there are definite examples of search result pages on very high authority websites like twitter appearing in Google search results, pointing to the fact that they are not entirely devalued if the instruction is not in place.
An ongoing debate rages in the SEO world over the Disallow instruction. Most believe that Google is forced to give no meaningful “link credit” to pages with the tag. Some say links in tweets can provide juice to the linked website, but there is no evidence other than correlational. To Value the links would be to disregard basic standards, very seriously undermining their credibility. Yes, Google does a lot that upsets SEO professionals, but for broad algorithmic decisions, they tend to stick to what they say publicly.