• by Laurie Sullivan  @lauriesullivan, June 6, 2012

Content shared from Facebook and the amount of backlinks appear to influence organic search engine results most, but Google +1s have the strongest impact on rankings on Google sites in the U.S. and U.K., notes a Searchmetrics study being released Thursday.

Keywords in the title or the header, word counts, title character length and an excessive amount of ads have negative effects. The study will show that similar factors have positive and negative influences on search engine optimization in both regions, although to different degrees.

In fact, there are some strong differences between the U.K. and U.S., specifically in the order of importance.

For instance, the number of words in the text has a large negative correlation in the U.S., yet less than half the correlation in the U.K. The report suggests that more highly ranked sites in the U.S. have less text compared with their counterparts in the U.K.

The study analyzes Google results for 10,000 popular keywords and 300,000 Web sites in the U.S. and the U.K. between February and March to identify correlations between content and search ranking. The results should help marketers better understand the close correlation between search and social content, as well as how Google algorithms Penguin and Panda influence change.

The data focuses on Google search engine page results because of the market share size, but Searchmetrics plans to add Bing and Yahoo in a later study. Matthias Bachor, director of marketing at Searchmetrics, said the ranking factors across engines are similar, as social continues to grow in importance.

"We think that social factors will gain even more importance in the future," Bachor said. "It will probably never replace other factors, like backlinks, but social remains a strong indicator for good content and will have an even stronger impact in the way we search in the future."

Bachor said it will lead to more personal results, depending on friends' networks, content that users like, and content being shared in their circles.

Regardless of the rising influence of social media, backlinks remain one of the most critical factors in achieving good search rankings. The number of backlinks remains the factor most strongly tied to positive rankings in both the U.S. and U.K.

The proportion of no follow links correlates more strongly with rankings than the proportion of links containing keywords in the U.S., but marketers will find nearly no difference between the two in the U.K.

Even the proportion of links containing a stop word can have an effect. This strong correlation for factors that seem to suggest a more natural link structure illustrates a trend suspected by many SEOs -- that dull, perfectly keyword-optimized links are often uneffective.

Ads are an obstacle. Too many or excessively clumsy advertisements have a negative effect on rankings. The negative correlation was slightly stronger in the U.K. at -0.05, compared with the U.S. at -0.04.

"We have seen that the existence of ads on the page correlates to rankings," Bachor said.

"This correlation value for AdSense integrations is much higher than for other ad integrations," Bachor said. "This means Google can easily identify the use of AdSense, but it also means the use of AdSense remains higher than other integrations."

When asked whether influences on desktop are the same as mobile sites for all three engines, Bachor said they are similar in some ways such as regionally, but different in others.