Palantir doesn't own any data whatsoever. It is in no way a data mining company, which makes it strange that it's constantly referred to as such. It makes software to allow organizations to do analysis on their own data, which Palantir has varying degrees of access to.
Another crucial difference is that marketing is a tertiary use case for Palantir, at best.
[1] http://www.nytimes.com/2012/06/17/technology/acxiom-the-quie...