One thought (out of the many you will get) would be to use stocks (trading at less than n.nn) that have individual boards on iHub. The reasons I suggest this are:
1) If members are talking about a stock, it is more significant to them.
2) If no-one will sponsor a stock by managing a board for it, it probably is not worth including.
3) Penny stocks have a tendency to be here today, gone tomorrow. If there is a board, it is more likely that the "gone tomorrow" ones will be identified and removed more quickly.
CopOut: These ideas are intrusive and stupid since I don't trade penny stocks and have only the most casual interest in them.
Fred