But Stuart Schuffman, 37, visibly blanches at being dubbed an “influencer.” While he acknowledges that he easily qualifies for the term, it’s not one he would assign himself.

“I’m not a skinny blond girl who looks good in a bikini,” jokes Schuffman, sitting at his desk in his SoMa apartment. “I get invited to a certain amount of influencer events, but not as many as some, given that the words ‘ass’ and ‘broke’ are in my name. A few weeks ago I was at an event for a private plane company and there were a lot of influencer types there.” He pulls up a photo of himself after deplaning the aircraft. “Every other person at this event posted the exact same photo of themselves in front of the jet like it was their own.”

Like it or not, as a tech and culture hub, San Francisco is known for a certain type of locally sourced influencer. Interior designer Ken Fulk, chef Tyler Florence and former Yahoo CEO Marissa Mayer are considered among the most important regionally (see sidebar), but their reach, and that of other influencers like them, is felt far beyond the Bay Area.

The term seemed inescapable in 2017. It was used in lifestyle press releases, invitations, stories and as a self-description on social media profiles. Its prevalence brings up questions such as: to influence whom and to what end? Can man live on influence alone? If an influencer posts an Instagram story in the forest but no one “likes” it, did it really happen? And, most obviously, what is an influencer?

“It’s broadly defined. It’s bloggers, it’s traditional media, it’s photographers, industry movers and shakers, people with huge social media followings,” says Jessica Mullens Engelman, the founder of Mullens Public Relations.

Fashion blogger and former boutique owner Kathleen Ensign, a.k.a. KatWalkSF, also wouldn’t call herself an influencer. This, despite that she has over 63,000 followers on Instagram (and 22,000-plus on her foodie account @KatFoodSF) and estimates that 30 to 40 percent of her social and blog posts are sponsored content — enough to make a living (in addition to some consulting work and an app project).

“When I think of who’s an influencer, I think of them as just being Instagram famous,” says Ensign, 31. “I have almost a negative connotation. I look at them and sometimes think, ‘They’re just attractive people who take good photos.’”

But public relations professionals like Mullens maintain that being an influencer is signifcantly more than posing and posting.

In the age of on-demand viewing (sans commercials), the decline in traditional print publications and greater electronic ad-blocking capabilities on websites, brands need new ways to reach audiences. The intimate and highly targeted reach of a lifestyle influencer’s self-selected followers is one way companies are reinventing PR strategies.

“Influencers can have an immediate impact and can create awareness in many forms,” Mullens says, noting the potentially high recognition payoff of social media posts from special events and Instagram-friendly installations like Color Factory, which she represented.

“An influencer now is really the vehicle to get the most eyeballs,” says Claudia Ross, the founder of Cross Marketing.

For many, the concept of the influencer isn’t entirely new: It’s a rebranding of a kind of social-business cross-pollination that’s been in existence for as long as the celebrity endorsement.

“Influencer has been a buzzword since roughly 2012,” says Allison Speer, the founder of Allison Speer Public Relations. Before starting her company, Speer worked for Armani in the 1990s and remembers the fashion house having special relationships with celebrities, like model-actress Lauren Hutton, who hosted events, wore the designer’s clothes and brought other A-listers into the company fold. The term then was “brand ambassador,” which Speer sees as a predecessor of the influencer concept.

Today’s influencers come in two varieties: macro and micro. A macro influencer is someone closer to a true celebrity in the traditional sense of the word: Reality star and megabrand Kim Kardashian, models and media personalities Kendall and Kylie Jenner, actress and Goop founder Gwyneth Paltrow and actor Jared Leto are all examples of famous individuals whose large social media followings make them ideal partners for brands.

“The term influencer in itself is a more Millennial-reaching term,” says Speer. “Fashion brands have always cultivated their friends and supporters, (and now) a lot of brands cultivating Millennials have been doing that with influencers to expand the generational reach.”

On the micro level, influencers can also be more homegrown professionals who have expanded their expertise in an area (fashion, interior design, food, technology, etc.) into a social media following that gives them the same kind of platform and wide audience.

“The asks I get from brands for store openings are always for tech influencers,” Speer says. “The tech people are our celebrities.”

Mullens, Speer and Ross agree that social media, specifically the visually oriented Instagram, is the essential vehicle that gives influencers their influence.

Although being an influencer may be more of a distinction than a career, some have leveraged the power of their status and social media followings into a lucrative side hustle, and occasionally even a full-time pursuit.

Marketing agencies like Influencer50, Collectively Inc. and Clever in San Francisco specialize in connecting brands to influencers and vice versa. It’s not just product giveaways, vacations and other services exchanging hands: Paid appearances at events like store openings and sponsored posts on social media have become so common in recent years the Federal Communications Commission weighed in with a set of guidelines in September for indicating sponsored content, saying advertisers have an obligation to disclose their relationship to consumers. These disclosures can either be indicated in the body of a post (sometimes via hashtag) or marked as sponsored content with an identifying label.

“Early on, like social media, influencer marketing was considered a gimmick,” says Mullens. “Now it’s accepted and part of the way we do business.”

But who benefits the most from the influencer-brand relationship?

Schuffman says that for the influencer, the rewards can be mixed.

“The business of media is broken,” Schuffman says. “On my website, an article needs 1,000 views before it makes a buck. Influencer marketing changed everything. People think they should get everything for free, so it’s harder to make money, but then they feel you’re a sellout for doing ads.”

In addition to sponsored content on his website and social media channels, in October Schuffman began using Patreon, a membership platform that allows artists and content creators to seek sponsorship from fans. He estimates the account is bringing in “about $1,200 a month, but it really needs to be at $4,500 to make everything completely sustainable. There’s sometimes so many influencers and not enough ad dollars.”

Ensign calls blogging and creating content across her social media platforms “a full-time job. I’m out almost every night; I plan my posts out. At this point I consider every offer (for sponsorship). Most just involve an Instagram post, but even those require work.”

“The reason you want an influencer is to sell product,” says Ross. “We’re in a merchandising world. As someone in public relations, I’m here to help my client sell. So many influencers have become so crafty to get the followers and the eyes on them. They’re young, stylish and they’re giving brands opportunities to display.”

In its simplest definition, says Mullens, “It’s about harnessing the power of individuals who have an influence over an audience.”

Tony Bravo is a San Francisco Chronicle staff writer. Email: tbravo@sfchronicle.com

Bay Area influencers (and their Instagrams) to know

ART

Jessica Silverman: Gallerist (Jessica Silverman Gallery); @jessicasilvermangallery

Yves Béhar and Sabrina Buell: Husband and wife industrial designer and art advisor (Zlot Buell); @yvesbehar

Zio Ziegler: Artist, @zioziegler

BEAUTY

Cassandra Bankson: YouTube beauty videoer, model; @cassandrabankson

Victor Cembellin: Senior artist, MAC Cosmetics; @victorcembellin

Chelsea Pearl: Beauty and lifestyle blogger; @chelseapearl

FASHION

Sherri McMullen: Owner of Oakland’s McMullen Boutique; @shopmcmullen

Tatiana Sorokko: Former runway model, Harper’s Baazar contributor; @tatianasorokko

Anh Sundstrom: Fashion blogger; @9to5chic

FOOD

Tyler and Tolan Florence: Husband and wife celebrity chef (Wayfare Tavern), Food Network host, and social figure and vice president of the Florence Group; @tylerflorence, @tolanflorence

Heidi Swanson: Cookbook author and blogger (101 Cookbooks); lifestyle expert; @heidijswanson

Alice Waters: Chez Panisse owner, food activist; @alicelouisewaters

INTERIOR DESIGN

Ken Fulk: Interior designer, author; @kenfulk

Erin Hiemstra: Interior and lifestyle blogger; @apartment34

Suzanne Tucker: Interior designer, Tucker and Marks; @suzanne_tucker

TECH

Jess Lee: Sequoia Capital investor, former Polyvore co-founder & CEO; @jesskah

Marissa Mayer: Tech executive, former Yahoo! president and CEO; @MarissaMayer

Kevin Systrom: CEO and co-founder of Instagram; @kevin