Adwords vs. analytics

Why don't they agree?

[deanjg]

I'm using Google Adwords for my site. My campaign summary shows that I received 9 clicks for a 3 day period. But when I review my Google Analytics report, it says that my site got only 2 clicks from search engines, and only 1 from Google.

What accounts for the descrepancy? I have Google analytics code on all my pages, and I only have one landing page, the homepage. Obviously I'm concerned because I'm paying a high CPC for my clicks, but if I'm not really getting them (per Analytics) then it is not good.

[deep_alley]

I have seen number discrepancies too but don't know why it happens.