I collected a dataset of more than 400,000 randomly selected Tweets and the number of times each tweet received a “new school” (native) ReTweet. I then compared 4 of the most popular ways to send images to Twitter: Facebook image links (images hosted on Facebook’s CDN, fbcdn-sphotos-h-a.akamaihd.net), Instagram, Twitpic and Twitter’s own, native image uploading service (shown in Tweets as pic.Twitter.com).
Tweets with images uploaded to pic.Twitter.com were nearly twice as likely to be retweeted while the use of Twitpic increased the odds by just over 60%. On the other hand Tweets that used Facebook or Instagram links were less likely to be retweeted. In all four of cases, I found a 99% confidence interval assuring us of the reliability of these results.