Over-the-Counter Bulletin Board (OTCBB) is an electronic community of market makers. Companies that fall off the NASDAQ often end up here. On the OTCBB, there are no «quantitative minimums» (no minimum annual sales or assets required to list).

Companies that list on the pink sheets (i.e. less than 300 shareholders) are not required to register with the SEC. Liquidity is often minimal. Also, keep in mind that these companies are not required to submit quarterly 10Qs.

Source: Investopedia, September 24, 2004, David Harper, Contributing Editor