In less than 20 years, the entire nature of Member-constituent communication has been transformed, perhaps more than in any other period in American history. Electronic technology has reduced the marginal cost of Member-constituent communications; unlike postal letters, Members can reach large numbers of constituents for a fixed cost, and constituents can reach Members at virtually no cost. The relay of information from Capitol Hill to the rest of the country (and vice versa) has been reduced to at times an instantaneous exchange. Members can now reach large numbers of citizens who are not their own constituents. These changes have wide-ranging implications for the work of Congress. How communication occurs, however, has changed significantly. Changes in congressional communications technology and use can be considered in three groups: 
1. historical communications (e.g., postal mail, telephone calls, press releases, and face-to-face meetings), 2. electronic communications (e.g., email and websites), and 3. social media (e.g., web 2.0, Twitter, Facebook, and other social media platforms). In addition to the adoption and use of Facebook and Twitter, Members of Congress and committees have begun to use other social media services. Likewise, information gets from Capitol Hill to the rest of the country much more quickly, to the point that as soon as something happens in Congress, it can be known everywhere in real time. Representatives and Senators are given a fixed amount of money—known as the Members' Representational Allowance (MRA) in the House and the Senators' Official Personnel and Office Expense Account (SOPOEA) in the Senate—for the hiring of staff, travel expenses to and from their district or state, constituent communications, and other office expenses. Electronic Communications Interact with a Wider Audience

Perhaps the greatest difference between traditional constituent communications and electronic communications is the change in the constituents reached. Traditionally, Members could only reach citizens who were actually their electoral constituents. Electronic communications, however, are not so limited. Challenges of Social Media for Members

As was discussed above under " The Nature of Electronic Communications ," the decision to adopt and use social media as a constituent communications tool has important implications for Member office operations. These include challenges in the areas of office operations, communications strategies, and constituent representation. Consequently, Representatives and Senators choose to allocate staff in different ways. Posting and Responding Policies

Over the past few years, many government agencies (especially in the executive branch) have adopted guidelines or rules for posting and responding to comments on social media platforms. These include the public nature of social media and further consequences for representation.
The mediums through which Members and constituents communicate have changed significantly over American history and continue to evolve today. Whereas most communications traditionally occurred through the media, via postal mail, or over a telephone, the adoption and use of electronic communications via email and social media technologies (e.g., Twitter, Facebook, YouTube, and other sites) changes how Representatives and Senators disseminate and gather information, who they communicate with, and what types of information they share and receive from the general public, many not residing in their district or state. In less than 20 years, the entire nature of Member-constituent communication has been transformed, perhaps more than in any other period in American history.
Over the last several years, the number of Representatives and Senators adopting social media and the number of different services being utilized has increased. In 2009, for example, Members of Congress were just beginning to adopt social media and only a small number were actively using Twitter, mostly as a dissemination tool. Today, all 100 Senators and almost all Representatives have adopted Twitter, Facebook, and other social media tools as a way to supplement their overall office communication strategies and disseminate information.
Electronic communication and social media differ from traditional Member-constituent communication in three key ways.
Electronic communication is inexpensive. Members can reach large numbers of constituents for a fixed cost, and constituents can reach Members at virtually zero cost. Electronic communication is fast. The relay of information from Capitol Hill to the rest of the country (and vice versa) has been reduced, time-wise. As soon as something happens in Congress, it can be known everywhere in real time. Electronic communication reaches a wide audience. Members can reach large numbers of citizens who are not their own constituents.
The cost, speed, and reach of social media have wide-ranging implications for the work of Congress. When Members choose to use electronic communication, they must consider many issues, including office operations (communications expectations and staff allocation); communications strategies (gathering and evaluating constituent opinions, content, interactivity, policies for posting and responding to content); and consequences for representation, including whether the office will respond to postings and, if so, how often. How an office evaluates and manages its social media presence varies from Member to Member.