ICQ shed more than 30% of its audience in 2013, reported its owner Mail.ru Group, an LSE-listed Russian Internet group, in its financial report for 2013. The global instant messaging service’s monthly user total shrank to 11 million across the world as of this past December, a notable contraction from 15.9 million a year before.

On the Russian market, the messenger recorded a loss of 31.7% in just a 12-month period with an estimated 6.7 million Russian users in December 2013.

The decline came as little surprise to the market, as it bore out a trend for the messenger that emerged two years ago. In its analogous report for 2012, Mail.ru Group showed a 41% year-on-year drop in ICQ’s global user base and a 37.6% falloff domestically by December 2012.

Building a user base “at a rate of 100 per second”

Even as ICQ was declining, millions of users have been registering with Telegram, a relative newcomer to the market masterminded by Pavel Durov, the founder of Russia’s largest social network, VKontakte, and his US-based company Digital Fortress.

The new messenger, which was rolled out last summer as a “faster and safer” English-only competitor to all existing messengers, passed the significant marker of 10+ million downloads as of February 21, 2014, according to Google Play stats.

Facebook’s $19 billion acquisition of WhatsApp appeared to give a great boost to Telegram’s recent upsurge. In the wake of the deal, many disappointed WhatsApp users have defected to Telegram. In Chile, Germany, Mexico, the Netherlands, Spain, and several others countries, this mobile messenger has even become the most downloaded application.

The growth in the application’s customer base is also evident from a steady flow of new user reviews on Google Play: some of the authors have been quite frank in their admission that they migrated to Telegram over the WhatsApp sale.

Mashable.com reported that on February 23, “the company added 4.95 million users on that day alone,” noting that “new users were registering at a rate of 100 per second.”

The influx immediately drove Telegram to sixth place on the iOS Top Charts of the world’s most downloaded apps. The messenger later slackened its pace, however, sliding by March 4 to the 18th position on Apple’s Topappcharts.com.

Among Telegram’s target groups are Internet users concerned with privacy issues. According to Durov, “messages sent through Telegram cannot be bugged by third parties,” as the messenger offers users “encryption protection too sophisticated even for security agencies to overcome.”

Last but not least, there is usability. Telegram is a cloud service, making it much faster than WhatsApp or Line. Another plus is that the application can be installed on several devices simultaneously, including on a desktop.