This isn't Chrome itself doing this, rather it's the website you went to. It's called re-targeting, basically, the website signs up with a third party advertising supplier (I believe Google also does this), they send small amounts of supposedly anonymous data from their site back to the advertising supplier in realtime. They set a cookie on your machine. Now anytime you go to a site that has signed up with the same supplier to show adverts, the ads are tailored to the fact that there's a cookie on your machine that says you went to Site XX, looked at Product YY.
Yes, it's a little freaky when you first see it, but believe it or not, these adverts do work quite well (unfortunately!)
This technology almost got me into trouble this year - I was looking on bluenile for engagement rings (my now fiancee didn't at this stage know I was going to propose!), they use similar technology and so I had a hard time explaining why, when she went to various websites, blue nile was advertised everywhere! Almost blew my suprise proposal!!