Facebook has announced agreement with 18 carriers in 14 countries worldwide to offer discounted data specifically for sending messages over the Facebook Messenger app available on both iOS and Android.

Essentially, since Facebook Messenger uses carrier data when not connected, Facebook is making it cheaper (or even free) for users on supported carriers. 

Among the carriers in the promotion are TMN in Portugal, Three in Ireland, Airtel and Reliance in India, Vivacom in Bulgaria, Backcell in Azerbaijan, Indosat and more. 

For users who don't own an iOS or Android smartphone for access to the app, Facebook and carriers are also extending the break to Facebook for Every Phone, which offers a Facebook experience on more than 2,500 feature phones. 

According to Pamela Clark-Dickson, senior analyst at Informa Telecoms, the promotion has the potential to reap benefits for both carriers and Facebook.

For the social networking giant, it will drive new users to download the Facebook Messenger app, giving the chance for new advertising revenues. As for the carriers, the analyst says they're all in developing markets and the promotion could give them an edge over their competitors. 

The promotion will be carrier specific to how much data will be discounted. At any rate, if you're on any of the supported carriers, time to download the Facebook Messenger app so your mobile bill can now let out a sigh of relief.