Maybe if the clan chat box lit up- or the player was notified (like with pms) then it would be more useful.
Are clans even big enough to need a clan chat?
In other games guild/clan/alliance chat was used for general game discussion (what does this do, how do you like this, how much does x item cost etc.), or to ask for help, or find others to play with.
Does goio as a game really need this? That I am unsure about.
I think it could be good for clans that dont use a voice chat program, e.g. skype or mumble. But only if players check it more regularly or are prompted to do it by notifications.