A lot of this has to do with these sites using ad networks instead of/along with selling ads directly. Ad networks are very common with consumer sites, but many

A lot of this has to do with these sites using ad networks instead of/along with selling ads directly. Ad networks are very common with consumer sites, but many B2B sites don't use any at all. When you work directly with the agency or company (and you know they're a real agency or company), this doesn't happen.