I generally find that personalised advertising misses the mark completely in my case. Sometimes it's because my browsing history doesn't match up with a product terribly well: there's not much you can sell based on half a day's research into the courtship rituals of the scimitar-horned oryx. But most of the time it's because they're sending advertising for things I've already dealt with and no longer have an interest in, such as the washing machine I've already bought or the Blu-ray I already own. I can't remember the last time I saw a personalised ad that made me think "actually, that's worth a look", whereas that happened fairly regularly before advertisers decided to start data mining.
It is also annoying when I have bought presents for teenage girls or husband has bought new bumper for the Morris MInor and it persists for years in trying to sell me Dr Martens or car spares!