The most up-to-date figures for the first eight weeks of the Channel 4 reality-TV show reveal a rise of 32.7 per cent in the number of customers signing up to Talk Talk.
The service now has more than 500,000 users and has become the UK's fastest-growing phone company since its inception in February 2003.
With its 16- to 34-year-old demographic and associated phone use on the show's voting element, Big Brother has become a strong platform for Talk Talk to grow further.
Off the back of this year's Big Brother-related success, the company has set a target of 900,000 subscriptions by March 2005.
Nine million viewers tuned in for the finale of the fifth series last week. An average of five million watched throughout the series, which incorporated more than 50 different Talk Talk ident executions.
Created by Clemmow Hornby Inge, the idents were part of a huge awareness drive around the fixed-line service, which has been set up in competition with BT.
Carphone Warehouse's aim is to make Talk Talk the number-one alternative to BT.
The executions, which were screened over the entire ten weeks of the show, appeared at the beginning and end of each show and were supported by ads in each break.
Featuring the presenter Andy Goldstein, they highlighted in a humorous way how Talk Talk customers can talk to each other for free.