I have bidded a word on adwords with exact match. When I log in to my AdWords account, I can see that the views for my ad for the specific word has been around 20 000 over a period of 1 month. I've had a Gen. Pos. at 1.5 but just got a CTR of 0.5%. Given that my ad is targeted to the specific keyword and has had such a good location, it seems like the numbers of how many times my ad has been shown is not correct. What is your experience?
My experience is that adwords reporting is correct. In fact, as the money of very big advertisers in involved, it's one of the most robust reporting systems around. Firstly - did you separate out search from display/content network? if you didn't I'd bet a pound to a penny that the vast majority of your impressions were on the display newtork, where it's very easy to get through hundreds of thousands of impressions with very few clicks. In itself, it's not harmful, and doesn't depress your quality Score or increase your costs.
I forgot to mention that this numbers is only for the search network. I doen´t advertise on the display newtork.
That is a very low CTR for search network. Maybe try to add more varieties of ads to attract more clicks? With average 1.5 in position, you can add "sitelinks" from your ad extension tab. Its a great way to put good keywords to attract clicks. Here's a brief documentation: https://adwords.google.com/support/aw/bin/topic.py?hl=en&topic=25441