I had given the test to my grandfather and his paternal grandparents both are at least half Cherokee. I never did get a response from ancestry.com as to why the results would not show any native american traces. Depending on what ancestry.com member you ask I either absolutely should have seen traces of native american or it's perfectly normal not to see any at all. If the ethnicity results are to be taken as some have said, 'with a huge grain of salt', maybe the price of the test should be dropped and/or advertisements shouldn't put so much emphasis on 'finding your ethnicity'. I also don't have a clue as to what time period the ethnicity results are coming from? 100-300 years ago? 400-1000 years ago? My family tree goes back to 1730 at the latest and some lines go back to the time of Charlemagne. Also, I have seen conflicting information as to the ability to distinguish between your paternal and maternal DNA results. I think at some point Ancestry.com offered three different tests but now offer only one. In the FAQ they say you can download your Y-data but in other place it says they only test the autosomal and the paternal (Y) information is not available for us to view.
I have bought a test for myself to see if any native american show up. I personally only recommend buying a DNA test as the last resort after all paper trails have stopped. The ethnicity results seem to be random and unreliable especially the autosomal test, the only one presently available for purchase.