Affiliate since: 12/31/1969, Power Rank: 99999999
One thing you can do is have a little contest, sort of like Biz Quiz, except the questions will all come from the announcement.
Post the questions, along with the announcement link, and see who can answer the questions. If you want to award prizes, fine. Even listing the top searchers in a Stream Post, along with some praise, can be very rewarding, as well as habit-forming at looking at announcements.
