What do you think of using keyword phrases that only have a Count and Predict of 2 or 3 in Wordtracker? This is a miniscule amount of potential traffic, but it may be easy to land top spot in the SERPs. A bunch of these low hanging fruit could lead to multiple streams of traffic for your site and add up.
Problem is, a word could get a count of 2 on a fluke in Wordtracker (someone just doing keyword research or a once in a long time search in Dogpile). When the count is this low, it seems that you can't really depend on the phrase really ever getting searched on regularly.
Thoughts? Do you have minimum Count threshold in Wordtracker?
Don't forget that WT only has a small cross section of keyword data, which is from Infospace (dogpile, webcrawler) so any result with a low number has a much higher chance of the predicted daily figure being skewed.
So best practice is to cross check with other tools that get their data from other sources such as Google, Keyword Discovery and Yahoo/Overture.