Bernie: It's well-reviewed (and I know several people who use it quite happily) but I've no personal experience of it. SC: To see what information your browser forwards to websites, click 'Start test' here: http://ip-check.info/?lang=en
Many (most?) commercial websites use, and share, ad-tracking cookies. So, for example if you search for a particular product on a website, and then come to AB, you're likely to find ads for similar products appearing here. Some people find it irritating but its what pays for sites like this one to keep going.
There's an option to 'tell sites that I do not want to be tracked' in Firefox under Tools > Options > Privacy.
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