Reports that Facebook is working on a social-networking phone has already been denied by a spokesperson for the company, but question is still there why the social networking giant enter the mobile phone arena.

To join the growing mobile market is becoming more and more important for any company whose business is based on the Internet because that is where the eyeballs are. As per the International Telecommunications Union’s estimates there are as many as five billion mobile phone subscribers in the world.

International Telecommunications Union has also predicted that around one billion of the mobile phone subscribers will be using their device on a wireless broadband connection by the end of this year. And the figure is expected to grow further quickly.

Companies such as Google and Facebook, whose businesses are based on Internet advertising, wants more and more eyeballs as the more the number of eyeballs, the more money companies will receive.

It makes sense that Facebook could develop its own phone in order to tap the fast-growing US mobile advertising market, where other companies like Apple and Google have recently made considerable moves.

Reports had claimed that Facebook had hit an agreement with hardware manufacturers and carriers to launch a Facebook-branded phone.

If Facebook really chooses develop a phone of its own, it will be a big test for the company as it will be company’s first physical product.