Tax Tip, especially for Louisiana

There is someone in St. Tammany Parish that has been willing to do real estate evaluations to get the R.E. Tax assessments reduced on over-assessed properties. I've heard that they have been successful with mostly commercial and it appears to be a profitable business. They'll do this for 60% of the amount saved. In one case, that I've heard of, on a commercial office building, the savings for the property owner was $3300. For the property owner, it's a repetitive savings. Does anyone know who is doing this?