PubMatic, a Palo Alto, Calif.-based company that works with online publishers to squeeze more revenue out of their advertising strategies, announced that it has brought in an undisclosed amount in a second round of funding from existing investors Draper Fisher Jurvetson, Nexus India Capital and Helion Ventures. The company, which partners with 5,500 publishers right now, says the money will be used to fuel worldwide expansion.

PubMatic offers a suite of tools to streamline publishers’ ad networks and cut down on the time it takes to manage them. For example, its Dynamic Frequency Optimization program predicts ad network pricing to get clients the best deal, and its Advanced Ad Quality Control product ensures that ads are not competing with a client’s direct sales force.