I find this method little hard to find campaigns. I scrolled through 3 pages of yahoo's posts and i see not any signatures campaigns or bounty campaigns to join. the thing is these people are also users of this forum not just managers. they do normal posts too.
I think best way is to just go to Services and join open campaigns . for bounties there is a section for bounties too. to join a good bounty just check which bounty token is listed in exchanges then join it.
i think checking their profile will be better than keep visiting the service section or bounty section if you really want to join on their campaign. Because you know most of their campaigns are always full and they post an update only if there's an open slot and it can be seen only on their thread.
However if we were talking about new campaign.. Then you must activate the notification on the both sections so that you will be notified when there's a new campaign from them.. But these days it's very hard to find mate, where in sometimes within a month there's no new campaign . So much better to visit their profile to see if there's an existing project with an open slot..