Not satisfied with its 1.8 million paying subscribers and estimated online revenues somewhere between $300 million and $700 million, Ancestry.com has found a new way to capitalize on the exploding interest in genealogy and DNA testing.The site will begin an invitation-only offer to paying subscribers to get a DNA test for a one-time fee of $99. The information from that test will then be incorporated into their Ancestry.com account, allowing them to see if they’re related to other members, as well as discover their ethnic roots.AncestryDNA.com, which offers the test, is not yet making it available to the public, but people can sign up to join a waiting list to receive an invite. By doing so, the site is not only upselling an integrated member service, it’s gathering new opt-ins and prospects — effectively killing two revenue birds with one marketing stone.Ancestry is basing its new offer on its 2007 acquisition for exclusive access to DNA assets from Sorenson Molecular Genealogy Foundation, a non-profit organization. However, the site should be careful. Another DNA testing service got in hot water for changing its terms of service on the fly. Not to mention the legal ramifications that can occur from knowing someone’s genetic information.Smart idea, Ancestry. But make sure your legal team is prepped and ready.