Domain-name holding company Oversee.net is getting a $150 million cash infusion from private equity firm Oak Hlll Capital Partners. Oversee has been on a buying spree lately, snapping up domain auctioneer SnapNames for $35 million last October and domain registrar Moniker for $65 million a couple weeks ago.

It also owns more than two million domain names, and no doubt will keep buying more. Overesee operates domain marketing services, including DomainSponsor, Revenue.net, and Low.com (mortgage lead generation). Buying domain portfolios and domain-related marketing businesses is becoming pretty capital intensive. As long as there is money to be made in online advertising, domainers like Oversee.net will continue to do well. But if a recession arrives and online advertising takes a hit, so will the domain-name sector.