Writing for Industry Gamers, David Radd has a two-part interview looking at how EA and Valve upped the ante in marketing the sequel in their hit zombie franchise, Left 4 Dead 2.

Radd talks to Valve’s VP of marketing Doug Lombardi, who outlines the plan to grow the audience for a quick sequel to what turned into last year’s number one selling new game IP in North America. The first step was allocating a bigger budget, with Radd pegging the marketing figure at $25 million. Lombardi says the budget allowed them to increase spending in Europe as well as direct more money towards broader campaigning through TV, online and billboard ads. One result was making Left 4 Dead 2 the most pre-ordered Valve game since Half Life 2.

For his second interview Radd delves into the game’s tremendously successful viral campaign, partly organized through social game community Kongregate. Kongregate helped create a zombie-themed game mimicking the type of games people play and share on Facebook, and ran a viral campaign called Infected Fury Month to support it. Radd talks to Kongregate’s chief revenue officer Lee Uniacke on how the campaign managed to attract more than 500,000 players and generate 1.2 billion impressions.