As an accessibility professional, I have come across a number of anecdotes demonstrating that good accessibility leads to a better experience for everyone; however solid research studies are difficult and expensive to perform. So when I was listening to Brendon Burchard the other day and he pointed out that his posts do better when they have higher contrast, I decided to test it out. I recorded the contrast of the 113 single image posts Brendon made to Facebook in January along with the number of likes and shares and then ran some simple analysis on them.
Contrast ratio is the measurement of the difference in contrast between two colors, in this case the text and background colors. I used Colour Contrast Analyzer from the Paciello Group to measure contrast and recommend it as a tool for anyone who would like to test their posts.
I only selected posts with a quote over a background to reduce variables. I excluded text and videos. This led to sample set of 113 posts. 53 posts had a textured background, 35 had a solid background and 25 had a photo as a background. When the background was textured or a photo, I sampled the contrast from the color that was most frequently placed behind the text. When there was any question, I always sampled the color that gave the highest contrast.
Of 113 posts, only 11 fell below the WCAG 2.0 AA recommended contrast of 4.5:1 so I chose to use the AAA level of 7:1 as the cutoff point of lower and higher contrast. This decision was partially guided by the small sample size and also by the fact that 7:1 better supports people with low vision than the 4.5:1. This article refers to posts with less than a 7:1 contrast ratio as lower contrast and any at or above 7:1 as higher contrast.
There were 21 lower contrast posts and 92 higher contrast posts. 24% of lower contrast posts received 1000 or more Likes, compared with 32% of higher contrast posts.
Posts get fewer shares than likes. When comparing posts that received more than 1000 shares, 5% of lower posts received 1000 or more Shares, compared with 27% of higher contrast posts. This was a small sample size of only 9 posts though so I also analyzed posts with over 500 shares which had 32 posts. In this case, 23% of lower contrast posts received 500 shares or more, compared with 29% of higher contrast posts.
There are a number of factors that cause a post to be shared and the content is likely the driving force. This was a very small sample size from a single author who tends to post higher contrast posts so the results are far from conclusive. That said, they are interesting enough to warrant more study.
In the meantime, ensure high contrast when you create posts that you want to reach a wide audience. This will help low vision users and users working in bright sunlight situations but it may also help boost your likes and shares.