It started simply. The most basic example is Facebook, which surfaces the most relevant content and information from friends and contacts. Not too long ago, Twitter revamped its Discovery tab and ’Who to Follow’ recommendations in an attempt to serve more relevant stories and other links on its platform.

Lots of commerce sites include a social feature, letting shoppers know what friends have purchased or recommended. Other commerce sites have enlisted the help of celebrities and industry influencers to curate or even create collections of goods and promote them accordingly, a la Rachel Zoe on Piperlime, or Mary-Kate and Ashley Olsen on StyleMint.

Some applications and products even go a step past recommendation, straight to authoritative delivery. For example, Soundrop is an application from SoundCloud that uses Spotify, allowing users to build and play social playlists. And for people (like me) who spend a solid portion of the day listening to music while working, lists of well-curated music are an easy way to get an hours-long soundtrack. This means that by listening to a socially curated list, you might not even know what you’re listening to — just where you’re listening to it. It’s sort of like listening to a movie soundtrack. While soundtracks are curated by a professional, these playlists are curated by friends and connections you trust. They work so well, that occasionally when asked, “What music are you listening to?” the answer is now, “Where are you listening to music?”

The same applies to shopping and purchasing decisions. Birchbox will send you a monthly shipment of beauty product samples. Stitchfix sends clothes tailored to your style. Wittlebee sends clothes tailored to your toddler’s style. If there were a service that sent my clothing recommendations culled from my best friends’ Svpply and Pinterest feeds, I’d probably take it!

Social recommendations are becoming an increasingly important way of doing business. So much so, that successful companies, products, and apps are iterating on the idea, introducing consumers and audiences into an environment where they are guided by these recommendations — often without realizing it. It goes right past understanding your audience, straight to serving them in the most personalized way possible.