Clients ask all the time about the effect of one change, link additional links, additional content, etc. on their search ranking. As an SEO Professional, I constantly warn clients not to expect huge changes with any one website or strategy tweak. I want to share the definitive answer on this question straight from the source-Google.
Google’s John Mueller said in a posting on Google Webmaster Help that a single change made to a site will not result in huge positive search ranking changes. John further outlined the fact that there are over 200 ranking factors, so one tweak is unlikely to change your search ranking. The full quote reads as follows:
Often there isn’t a single “tweak” that can be made to a website to automatically make it jump up in rankings — we use well over 200 factors in crawling, indexing, and ranking, and it’s always good to work on the small things as well. When looking at the bigger picture, it’s useful to really take a step back, and to try to see what could be changed overall to improve the quality of the content (when it comes to our algorithms), especially with regards to the content that’s indexed.
Bottom Line: It is best for you to do a website evaluation, check for unique and user friendly content, and the quality of the link structure as a whole. Also, look to improve the frequency and quality of site updates rather than look for one quick and easy fix for your website.