PEW Internet has released an up to date study on Twitter usage in the USA. According to the study Twitter again is growing strong, about 50 % since November 2011. The microblogging service is now used by 13 % of the population opposed to 8 % in November. The use in the group of 25-34 years old even doubled. Interesting again is a figure about mobile usage, which is applied by a half of the members. Below is an excerpt and a link to download the study.