In researching my Lewis line over the past ten years, I've come across many web sites for "professional" genealogists, those who offer to do genealogical research for hire. Most of them are legitimate, with real credentials and a track record to demonstrate their expertise.
I have also come across web sites for those who are obviously not professional genealogists, yet who make the claim and offer to do genealogical research for hire.
How can one tell the difference? How can one who really would like some help in the details of intricate genealogical research sift the legitimate genealogists from those simply posing as genealogists for their own reasons?
First of all, genealogy is a discipline based on documentation. Any web site that makes claims of genealogical connections based on heresay, rumor, innuendo, supposition or guesswork is not run by a professional genealogist. A genealogist answers questions with documentation and does not pose hypothetical questions of dubious historical connections. Any genealogists who claims great antiquity to many historical figures is also not a professional, in that deep antiquity cannot be proven, in the absence of very rare and highly unusual documentation.
Another good clue is a raft of genealogical "awards" displayed on the web site, especially when the "award" graphics do not link to any organization or web site, but are merely there for display and personal aggrandizement.
Genealogy is a labor of love, a task many of us take for on our own satisfaction, not to line our pockets with pecuniary recompense. We give our research to others for free, for personal satisfaction and for the love of our families.
Beware of genealogists bearing great gifts! If they seem to good to be true, they probably are.