Before you choose the contact discovery researcher, make sure you know something of their track record. Your ROI should justify the money spent. This is one field where experience and reputation matter since personal information is being garnered. Check whether the lists they provide are current or just old wine in new bottle. Companies seem to favor technology but nothing can replace experience when it comes to contact discovery. Old hands at using technology to their advantage can be relied upon.
Before you make your choice of the company who will procure contact discovery for you take a look at the way they go about it. Dedicated teams that use cutting edge technology to track evaluate and analyze contacts. If you are handed over half-baked contact information, the sales team will be spending time chasing mirages instead of filling the funnel. Contact discovery is not a task for novices who spend time without producing concrete quantifiable results.