Ancestry.com has an awesome new tool (beta version at this point) to combine autosomal genetics and classic family-tree based genealogy. The tool is called ThruLines (tm). You can read about it at the link below-
ThruLines more or less supersedes the DNA Circle tools and I found it much better in terms of identifying on Sproul and Belding cousins and graphically portraying our lineages and relationships. Ancestry.com does not offer the powerful mtDNA and Y-DNA tests and tools that FTDN does - but if you are doing serious work on genealogy linked to autosomal DNA (family matching) you cannot beat Ancestry. I provide a screen shot of the results and quote from Ancestry -
How it Works
We use the public or private and searchable family tree linked to your test to find people who are in both your tree and in other Ancestry member trees that are marked as public or private and searchable. If your tree is private and not searchable, you won't be able to see ThruLines, and information from your matches' trees that are private and not searchable won't be available to you.
DNA matches can appear in more than one ThruLine.
From any page on Ancestry, click the DNA tab and select Your DNA Results Summary.
From your DNA homepage, click Your ThruLines.
On your ThruLines page, you'll see how you may be related to your DNA matches through common ancestors. Click on a person to see which DNA matches may be related to you through the person you selected.
The number of your DNA matches who could be related to you through this ancestor will be listed on the top of the page. You can toggle between the Relationships view and a list of the person's children (A). In the Relationships view, the person you clicked on will appear at the top (B). Everyone who has the DNA symbol (C) by their name is one of your DNA matches. If you see a number with an arrow by it (D), click on it to expand it. People who appear as "Private" (E) are either living people or people from private but searchable family trees. If you click on anyone on this page, you'll need a subscription to see more about them.
Ancestors from your linked tree will appear at the top of your ThruLines, but if you scroll down far enough, you'll start seeing people with dotted lines around their names. These are potential ancestors—people who aren't currently in your linked tree, but who are listed in other Ancestry member trees. You can also filter your list by potential ancestors and ancestors from your linked tree.
Since ThruLines are based on the family trees of you and other members of Ancestry, they're as accurate as the trees they're based on. Errors in family trees can cause inaccurate ThruLines.
Because they're based on trees, ThruLines also don't prove your specific connection to a DNA match. For example, if you have someone listed in your tree as a second cousin, and that person appears as a DNA match and in a ThruLine as your second cousin, they could still actually be a first cousin once removed, a half-first cousin, or a number of other relationships to you.
Click the amount of DNA you share with a match to see a list of likely relationships for you how you may be related. This chart also shows how often a likely relationship happens based on the amount of shared DNA." (text and graphic from Ancestry.com)