Keyword not in my list triggering ads

[MediaSpree]

Well I looked at my logs as I often do and saw that several people were coming to my website after searching for "widget x" which is my competitor if you will. Interesting I thought so I went to google and typed "widget x" and, along with some other adwords ads on the right hand side, mine is included. I never bid on "widget x". I bid on the more general terms in the niche. and while I don't mind the extra traffic... how much am I paying whne someone clicks this ad on a keyword which while realted, is not neccesarily what I want people to search for to find me? Are the clicks free (yeah, right!)? Is this even possible? What am I missing?

Help!

[AdWordsAdvisor]

MediaSpree, I'd guess that you are using broad match for the keyword 'widget', and are seeing 'widget x' as a result.

Briefly, you probably want to explore the different keyword matching options available to you, and also employ negative keywords to prevent your ads from showing for searches you know you'd rather not show on.

More info from the AdWords Help Center:

What are keyword matching options?
[adwords.google.com...]

How do I choose negative keywords?
[adwords.google.com...]

AWA