Ancestry.com, etc.

[Sportster]

I never wanted to do it and have my DNA for sale to whomever. But, my sister did. Not much I didn't know with one exception,
55% Scotland, Wales, Ireland (read Celtic)
8% Scandinavian (read Viking)
35% Western European (read German)
2% Eastern European (no clue)
They also indicated my kin folk first arrived in the "New world" - Massachusetts, in 1650. Not exactly sure how they know that but a guess would be from someone who did a ancestral trace.

[BurntBulb]

The problem with these sites, you pay to have your genome mapped, thus it no longer belongs to you.
Thing is, it doesn't even have to be yours anymore. Your DNA is known without having tested you.
Long dead DNA is testable and statistical. As an example I give you Neanderthals.
Except the Sub-Saharan African, that has no Neanderthal DNA, because they never left Africa, and Neanderthals didn't invade.
All human races, sub-races ,tribes, and families, have on average 2% to 2.5% of Neanderthal DNA.
The island Polynesians and the Indigenous Americans have 2.5% to 4% Neanderthal DNA.
Give us Homo Sapiens time enough, to create the species that will displace us,
our and the Neanderthal DNA will still be there.