Ad operator ValueClick has agreed to pay up to $452 million dollars to acquire comparison shopping site operator MeziMedia, reports ClickZ.

The deal would bring MeziMedia's management team into ValueClick, which would immediately gain access to MeziMedia's stable of shopping comparison sites.

Such sites, which offer searchers a listing of price differences at various retailers, are viewed by ValueClick as a form of search marketing. Revenue on such sites is generated by running ads on a PPC model.

MeziMedia's veteran management and staff would also be an advantage to the building out and up of the comparison site ValueClick runs, PriceRunner.com. They will also, ValueClick says, be able to help add to the expertise in the use of search in other e-commerce areas.

ValueClick will pay $100 million up front for MeziMedia, with another $352 million up for grabs based on the acquired company meeting performance benchmarks.