Grassroots marketing and guerrilla marketing are very similar. They both aim to spread the word about a company or public figure by engaging the masses. Guerrilla marketing is a term coined by Jay Conrad Levinson to stand for marketing that requires a lot of time and energy to execute by a company without a large budget. Grassroots marketing involves campaigns that start with, or spread slowly through, the masses, with little interference from the the company being marketed.
Grassroots marketing can be started by an internal marketing department, marketing agency or simply by company supporters. Often these supporters include influential customers like celebrities or popular bloggers. However, any large group of people expressing their support for a company or public figure at the same time can be an example of grassroots marketing. They key component to grassroots marketing run by fans or customers is that they all organize for a specific purpose: getting others to make a purchase, cast a vote or take some other course of action. Guerrilla marketing always begins with the company or a marketing agency.
Grassroots marketing takes a quiet approach to spreading the message about a company. Tactics include passing out merchandise with a company logo on it, launching a sponsored website, and blogging about a topic and including the company name in posts. Grassroots marketing ensures a company’s message is in front of its target audience so often that they begin inquiring about the company. Guerrilla marketing tactics include passing out coupons or running contests. It says, "if you engage with us, here’s how we will reward you."
When grassroots marketing is initiated by the masses, it comes at no cost to the company unless it chooses to get involved. For example, if a customer makes a video about a company and it goes viral, the company may wish to choose to purchase the video. However, all production and distribution of the video up to that point was paid for by the customer. Grassroots marketing not started by the masses and all forms of guerrilla marketing are paid for by the company wishing to run the campaigns.
The overall goal of both grassroots and guerrilla marketing is to increase sales and brand awareness. However, in the case of grassroots marketing started by the masses, the initial intended goal may have been to simply create something fun, like a video or funny image, to support a company or cause. The intended goal for all marketing programs started by the company or its marketing agency will be to increase sales and brand awareness from the beginning.