The two-step flow theory which was first suggested by Paul Lazarsfeld, the sociologist, in 1944, then was elaborated with Elihu Katz in 1955. It shows how the mass media influences the audience in two steps. First, the mass media is noticed by the people who are interested, we might call them “influencers” or “opinion leaders”. Then, they will pass the media message to the audiences, inside this theory, the audiences are active in the communication process. The people who have the most access to and understanding of the media will diffuse and explain to the others, just like when we are planning the traveling, will ask the people who know the most about those places and ask them to give you some recommendations rather than search by yourself and believe the information on the internet.
Paul Lazarsfeld 
Elihu Katz 
In the contemporary media, there are a lot of examples of the two-step flow theory. On the most common social media platform, Instagram, there are many influencers who will help to sell some products from a company that is not related to them. For example, as a skincare institution, the company will send a request and some samples to the influencers to ask them to help share about the products. Then influencers will make a post or a story about how they are using some skincare products that are really great, the ‘before’ and ‘after’, and have a promotion code for their audiences. After the audience sees the post, they will buy it with the promotion code as the influencer who knows her daily life from her post, they think that the thoughts after use are true. That is the two-step theory, first, the influencers will notice the products then share them on social media, and next, the followers will get the information about the products on social media, not the website of the products or company.
According to the article ‘Who Says What to Whom on Twitter’ by Shaomei Wu et al, they found that there is almost half of the news is passed through the influencers to the audiences, also their Twitter account is more exposed to the media than their followers, even though they are just normal users. This study supported the two-step flow theory, that the news is passing from the first step, the influences, then to the second step, to the audiences.
Therefore, the two-step flow theory surrounds our daily life, especially on social media platforms, there are a lot of media messages we know are from the influencers to send to us rather than the mass media itself.
This blog post provides an interesting overview of the Two-Step Flow Theory, which suggests that media messages are filtered through opinion leaders before they reach the general public. You did a great job of providing an overview of this theory and its implications for communication research. Additionally, I appreciate how this blog includes examples to illustrate key points, and it helps better understand this concept. Overall, it is a well-written piece that effectively explains the two-step flow theory in media studies!