Superficially seeding an online community is easy. Find 5 big topics and write about them. Leave a few open-ended questions. But this misses the point.
Seeding an online community should be cultivating a group of 10 to 20 people who are creating the first discussion posts, launching polls and interacting. They are the core people. They are the rocks that can you rely upon to continue stimulating activity in those rocky early days.
If you do this right, you offer members more than a glimpse of what future discussions will look like, you offer newcomers a glimpse to what the future community will look like.