Dec 1, 2010 18:46 GMT  ·  By

Opera is celebrating an important milestone in the company's history, it now has over 150 million users. That's users in total, counting desktop, as well as mobile users, but it's still an impressive figure for the Norwegian software maker. More interesting than the actual number though is how the company decided to announce it, by posting a working copy of the company co-founder and former CEO's inbox on the homepage.

The first message in the inbox: an out of office automatic reply, notifying him that the PR team is currently out celebrating.

"The PR-team is currently out of office celebrating Opera reaching 150 million users! Leave a message and I will get back to you asap! If urgent, we are probably down by the pub in Waldemar Thranes gate called 'Tranen'," the email reply reads.

That's in response to co-founder's Jon von Tetzchner message about needing to spread the news of the milestone.

Of course, it's not Tetzchner's real inbox, presumably, but a very clever way of getting some buzz. It way more effective than a press release, that's for sure.

You can browse through Tetzchner's inbox and read all of the previous messages, all of which are pretty funny.

As for the number itself, 150 million is impressive, but Opera is dwarfed by other popular browsers out there, on the desktop front. Firefox, Chrome and Safari all have significantly more market share than Opera on the desktop.

However, Opera Mini is hugely popular with feature phones with more people using Opera on their phones rather than desktops. And a lot of people are using Opera browsers on consumer electronics devices such as the Nintendo Wii.

Opera announced that it had 140 million users in September and provided more detailed numbers at the time.