TagMan, a London-based startup that helps advertisers track the performance of their online campaigns, has raised $1.3 million in a first round of funding led by Cambridge Angels and the London Business School’s angel investor network; several existing employee investors also participated in the round.

Advertisers use TagMan’s system to manage “tags”—pieces of code put on web pages in order to track how visitors arrive there. By keeping accurate tabs on that data, advertisers can appropriatey pay out commissions. Customers include Virgin Atlantic, travel agency Thomas Cook, and interactive agency Media Contacts.