Expert networks are primary research firms that connect buy side investors, consultants, and business decision-makers with industry experts. Consultations between expert network clients and experts may be in the form of "face-to-face meetings, phone calls, teleconferences, video conferences, [or] email exchanges." According to a 2009 report by Integrity Research, there are at least 38 expert network providers worldwide. Although most expert networks operate across verticals and geographies, recent trends point towards specialized expert networks serving a particular geography or vertical.