The most important part of this process is registering your kit before shipping it. All five services require this, and if you don't do it, you won't be able to access your results. This requirement is to protect your privacy—your name won't appear on the kit or the results—and to easily track your kit as it goes through the process. Of course, when you sign up for an account with these services, your identity will be associated with it, but the sample and any reports stored on the service's end will just have a unique barcode.
Each ancestry DNA service has its own sample database and reference panel made of the DNA samples collected from their users and information collected from sources like the 1000 Genomes Project. The database consists of all this information collectively. A reference panel is made of certain curated samples with known family history and roots in a specific place. The services use insights gleaned from the reference panel to give you geographical ancestry results. In theory, a larger database leads to more information available to create a good reference panel, which then leads to better results for customers.  

As my dad and I have begun to explore our genealogy over the past seven years or so, we’ve found that our family is largely from Spain, which is no big surprise. Colombians have a wide range of ethnicities, which explains why many Colombians, including my mother, have white or fair skin with blue eyes. My dad also suspects we have German ancestry somewhere back there.
Hi Mark, can you tell me which test my mother in law would need to take, for me to find genealogical information on her paternal line? She never knew who her birth father was apart from the fact that he was an American serviceman stationed in England after WW1. She has no siblings. Is there a test suited for this? As she is nearing 100 years old, it would need to be a cheek swab test. Would it be beneficial to have my husband tested instead? Thanks.
It could be that, in the main, genetic-testing kits such as these could, if promoted and used responsibly, end up zoned completely away from legitimate science and medicine and placed where perhaps they belong, firmly in the lifestyle-extra zone, if and when people think they’re “worth it”. Though, somewhat tellingly, when I ask Newman if he thinks that any of the genetic testing kits are worth buying, he instantly says: “No. I’d say, go to the cinema, watch some sport. Spend the money on something nice, something life-enhancing.”
4. Geno 2.0: At $199 National Geographic’s Genographic Project is the most expensive of all of the choices and is also not deigned specifically for genealogists. They do not offer a database of known relations and the data they provide is more general in nature. However, joining the project does provide a geographic ancestry breakdown as well as a report on how much Neanderthal you may have (fun!). It is an exciting scientific endeavor and definitely worth exploring and joining if you have the resources to do so. Find it here.