TalkTalk customers have already made more than 530,000 calls using the Talk2Go app, which allows them to use inclusive landline minutes on their mobile.
In total, the free app has handled more than three million minutes worth of calls since it launched in December 2014.
TalkTalk said its customers have been taking advantage of its "great value" calling boosts, especially the 500 Global Minutes Boost, to call countries around the world.
These range from Austria to Australia, the USA to Uruguay and Romania to Russia, the broadband provider noted.
"Calls to mobile phones overseas are the most popular, with customers making around 4,000 every day, followed by calls to landlines overseas, then calls to UK mobiles and calls to UK landline phones," TalkTalk stated.
The firm explained that, like all TalkTalk Boosts, its add-ons can be purchased one month at a time, with no ongoing commitment.
"Other customers are using our Mobile Minutes Boost and Anytime Calls Boost, so they can save money on expensive mobile phone bills," TalkTalk stated.