In practical terms, a media kit (sometimes referred to as a press kit) is a gathering of important information that potential advertisers/sponsors would want to know about your blog/website/social following. It gives them a quick rundown of what you’re about, and who your audience is.
In all honesty, you don’t need a media kit per se. If you are totally content to just write your blog or make content for for your followers as a way to bring in more projects, that is totally fine and a valid. But, if you’re looking to monetize or grow your blog or social accounts with partnerships, sponsorships, product reviews (which often come with free products- yay!), advertisements, sponsored trips to trade shows, etc. the companies who are going to be funding this are going to want to make sure you are the right fit for their target audience.
Now this will depend heavily on what type of opportunities you’re hoping to nail down, but here’s a general idea of what you should include in your media kit:
* Side note, another great way to monetize your blog is with by participating in affiliate programs for products you’re a fan of.