You want to know what others like you are doing.
So you need a news page. You need to create the a place where people come to find out what others like them are doing.
You need to segment beyond just the topic interest. Consider using internal characteristics that people feel are important. e.g. age, location, income, job roles, gender etc… i.e. Instead of a community for people working in technology, consider, tech PR, under 30 in tech, in London Tech, female in tech etc…
The opportunities are limitless. If you are an account executive at a marketing agency, you would probably read a news page talking only about account executives at marketing agencies.
Create the news page, enable comments, interview people frequently and as you build up traffic expand to add a forum.