Social Networking Service (SNS)

A social networking service (SNS) or social networking site is an online platform which people use to build social networks or social relations with other people who share similar personal or career interests, activities, backgrounds or real-life connections.

Key Features

While they vary wildly, most SNSs share these core features:

1. Public/Semi-Public Profile: Users can create a profile with bio, photo, etc.

2. List of Connections: Users can articulate a list of other users with whom they share a connection (Friends, Followers, Contacts).

3. Viewable Connections: Users can view and traverse their list of connections and those made by others within the system.

4. Content Sharing: The ability to post text, photos, video, or links.

Sociology

Social networks capitalize on the "network effect"—the idea that a service becomes more valuable as more people use it.

• Dunbar's Number: A theory suggesting humans can only maintain stable social relationships with about 150 people. Social media challenges this by allowing us to "connect" with thousands, though the quality of these connections is often debated.

Business Models

• Advertising: Selling user attention and data to advertisers (Facebook, Instagram, Twitter).
• Freemium: Basic service is free, but advanced features cost money (LinkedIn Premium).
• Subscription: Users pay a monthly fee (rare for general social networks, more common for niche dating sites).