Let's get the bad out of the way first. The cover, I like the cover a lot, but it has very little to do with the content.
Interior art. Overall...its really bad. Which is a great pity.
Lastly its pretty short at 66 pages. Over pirate rpg's push over the 200 page count. So there is a great deal they could have done and didn't. Like adding the hollywood pirate mythos which while shown on the cover isn't in the interior.
Now the good.
The content while short is good. It covers by and large real historical piracy, The places, the reasons, some politics and economics. While its more a primer its still very well written and gives a good overview if you knew little about pirates. Which is a shame as to the page count. The guy can write in a fun and informative manner. It would have been nice to have had more as it was a pleasure to read.
The book is well thought out and does give you enough new D20 material to recreate pirates in your games.
The price. At 16.95 that would be a hard sell, But at 3.00 its excellent value.
A larger page count with more content and better interior art would have made this a great sourcebook. But its solid content, ease of read and price does still make it a worthwhile purchase. and one you shouldn't regret.