Since many of our products and services are purpose-built for a niche community, I find that many of the keywords I am researching are all low-volume. Data on the Keyword Difficulty Tool show '0' under Bing Search Volume (exact match). I know what my competitors are targeting based on their title tags and web content, but I'm not sure if they did their keyword research homework, so I don't want to assume. Is there any other way to determine which keywords I should be targeting?