There’s a story on the BBC about Tory MP Louise Mensch resigning, and it talks about her ‘Not Twitter, honest’ social network, Menshn:

Mrs Mensch was a prolific user of the micro-blogging site [Twitter] with 102,000 followers.

But she said recently she had grown “frustrated” with it and has set up a rival site – Menshn – which aims to keep conversations on topic and allow people to post 180 character messages – 40 more than Twitter.

There have been plenty of reports that have either failed to qualify the 180 character thing or have cited it as some kind of added value. Even all this time after Menshn launched, I find the 180 character decision arbitrary and odd. I can only assume Mensch and co. didn’t want to go for 140 through fear of being sued (or it being even more obvious about the service’s attempts to ‘clone’ Twitter). And so 180 was presumably plucked out of the air, because more equals better equals value equals PROFIT!? But Twitter chose 140 characters for a specific purpose: to enable compatibility with SMS.

Twitter’s now looking likely to move away from its roots, with things like expanded tweets, but the 140-character limit remains, enabling people using feature phones to still engage with the service. Menshn on the other hand remains lodged in a broken version of Twitter’s past, and lacks the ability to embrace what Twitter foresees as its future. It’s a strong lesson that decisions need to be more than arbitrary in order to make sense but also provide a service that enables more users to become involved.