Want to be Retweeted? Add URLs to Your Tweets!

In my previous post, I described a recent study [1] in which we found that including hashtags in a tweet may enhance the retweetability of the tweet. In this post, I will focus on another factor that might affect the retweetability: URL.

As reported in my previous post, we collected a random sample of public tweets from Twitter's Spritzer feed over a 7-week period, yielding about 74 million tweets. From these tweets, we identified 8.24 million of them as retweets. That is, 11.1% of the 74 million tweets are retweets.

Next, we searched for those tweets and retweets that contain at least one URL. We found that 21.1% of tweets and 28.4% of retweets include URLs, suggesting that a tweet with URLs is more likely to get retweeted.

We further investigated whether the retweetability of a tweet has anything to do with the type of website it refers to. Since most of the URLs included in tweets are shortened URLs, we first expanded the abbreviated URLs into their original URLs, and then extracted the domain names from the original URLs. For example, given an abbreviated URL http://bit.ly/c1htE cited by a tweet, we first unshortened it to http://en.wikipedia.org/wiki/URL_shortening, and then extracted the domain name of en.wikipedia.org. The URL domains are indicative of the type of content sources visited and shared by Twitter users.

Analyzing the 74 million tweets, we identified the 20 most popular URL domains referred to in our tweets and the number of tweets containing each URL domain:

Rank	URL Domain	Number of Tweets
1	twitpic.com	793,680
2	myloc.me	533,082
3	www.facebook.com	481,349
4	www.youtube.com	475,509
5	formspring.me	455,377
6	www.twitlonger.com	349,760
7	tweetphoto.com	258,049
8	youtu.be	196,557
9	twitcam.com	159,684
10	url4.eu	145,656
11	twitter.com	144,002
12	www.plurk.com	127,037
13	fun140.com	113,153
14	www.formspring.me	100,111
15	bit.ly	94,505
16	foursquare.com	90,328
17	www.ustream.tv	83,486
18	tinychat.com	80,406
19	blip.fm	74,647
20	www.funwebsites.org	52,148

On the other hand, the following table shows the 20 most popular URL domains cited in our 8.24 million retweets and the number of retweets containing each URL domain:

Rank	URL Domain	Number of Retweets
1	www.twitlonger.com	236,435
2	twitpic.com	129,692
3	myloc.me	121,950
4	www.youtube.com	79,404
5	www.facebook.com	55,186
6	tweetphoto.com	49,676
7	twitter.com	39,127
8	mashable.com	17,778
9	bit.ly	16,406
10	www.ustream.tv	9,638
11	www.nytimes.com	9,035
12	shar.es	8,636
13	url4.eu	8,213
14	dealspl.us	8,186
15	www.flickr.com	7,599
16	www.cnn.com	7,537
17	youtu.be	7,508
18	www.etsy.com	6,828
19	ax.itunes.apple.com	6,346
20	www.huffingtonpost.com	6,332

As can be seen, these two lists of URL domains do not match each other exactly. For example, formspring.me appears only in the first list, while mashable.com appears only in the second list. That is, the fact that a website is frequently cited in the tweets does not guarantee that it is also frequently referred to in the reweets, and vice versa.

For each URL domain, we computed a retweet rate by dividing the number of retweets containing the domain by the number of tweets containing the domain. We then normalized the rate so that a value of 1.0 represents the average retweet rate of 11.1%. For example, for twitpic.com, the retweet rate of 1.47 was calculated as (129,692/793,680)*(74/8.24). A URL domain with a retweet rate higher than 1.0 indicates that, compared to the average case, the tweets containing this domain have a higher chance of getting retweeted. The following table shows the retweet rates for the 10 most popular URL domains cited in our tweets:

Rank	URL Domain	Retweet Rate
1	twitpic.com	1.47
2	myloc.me	2.05
3	www.facebook.com	1.03
4	www.youtube.com	1.50
5	formspring.me	0.05
6	www.twitlonger.com	6.07
7	tweetphoto.com	1.73
8	youtu.be	0.34
9	twitcam.com	0.12
10	url4.eu	0.51

As can be seen from the above table, the retweet rates vary greatly depending on the URL domains. For example, formspring.me, which is the 5th most popular domain, has a retweet rate of 0.05, suggesting that tweets containing that domain are very unlikely to be retweeted. On the other hand, the retweet rate of twitlonger.com is 6.07, suggesting that tweets containing that domain have high retweetability.

In the following plot, we show the retweet rates of the 50 most popular URL domains. The X-axis is the popularity rank of URL domains based on how many tweets contain each domain. The Y-axis represents the retweet rates of domains as computed above.


Overall, we see that not all popular URL domains in tweets are popular in retweets. The domain of URLs also matters.

References
[1] Suh, B., Hong, L., Pirolli, P., and Chi, E. H. Want to be Retweeted? Large Scale Analytics on Factors Impacting Retweet in Twitter Network. To appear in SocialCom'10.