We all love to look and are happy to share cute infographics. But before you write a blog post based on an infographics, make sure to check the hyperlink that it points to and that you can find the data source.
Best practices suggest that you include in your post a link to the data sources. This way, you and your readers will be able to decide if the statistics are reliable or not. You can also explore other aspects of the surveys that were not depicted. I believe that the data sources should always be written on the infographics.
I also want to point out a trend where some use the appeal to infographics as a bait for link building. So be careful and check first.
If you are looking to know more about the design of infographics, you can visit Cool Infographics, a blog dedicated to the topic.