New to Adwords, and at a loss with Wordtracker

I'm using the free version of wordtracker while I'm still learning (top results of MSN.. and I'm just assuming there would be a same, or higher number of people searching on google for the same thing)
From that i've found a keyphrase that has a very high search rate with very low competition.
I have the product for sale, so I wrote an Ad, put the phrase in keywords, in every imaginable combination with broad and exact matches - and in two days I've only had 13 impressions, and one click. According to Wordtracker there should be AT LEAST 69 impressions per day on MSN alone. It has a KEI analysis of 7000 (which is supposed to be excellent!) I really don't understand, google is displaying my ad when i do the search, so it must be Wordtracker... is the free version not accurate? I certainly don't want to pay for it if it's not going to help me?
Maybe I'm doing something wrong, or there's a gap in my understanding?

Appreciate any advice! Brad

AdWords may limit impressions of your ads if your daily budget is too low. Try setting it well in excess of what their suggestion is. Also be sure that your bidding enough per click to appear in the top 8 on average.

AdWords #s will always be more accurate for search volume on Google than Wordtracker. Wordtracker takes search volume data from two meta search engines and tries to estimate search volume for other engines via statistical extrapolation. It does not account for user base demographics and IMO, is not useful for predicting search volume most of the time.

Cool, thx Bernard.. that makes sense and useful info for wordtracker - will make some changes

Brad