[PHIA] One Year In Review: What a Million Users Tells Us About Sustainable Marketing
We wrote about Phia when it first launched in early 2025. At the time, the app had around 100,000 users, $850,000 in seed funding, and a marketing approach that we found genuinely interesting: a sustainability-driven product that deliberately chose not to lead with sustainability.
A year on, we wanted to dive again into their brilliant marketing strategies to see if our thesis held up.
What has changed in a year
Phia has now surpassed one million users, partnered with over 6,200 brands, and scaled to tens of millions in monthly monetised GMV.
By September 2025, the company raised $8 million in a seed roundled by Kleiner Perkins, with investors including Hailey Bieber, Kris Jenner, Sheryl Sandberg, and Sara Blakely.
That is a meaningful shift from the early angel round backed primarily by Kris Jenner and Sara Blakely. Kleiner Perkins leading a round is a signal that the venture capital world sees real infrastructure potential here, not just a Gen Z-friendly app with a famous founder.
For context on what the product actually does: Phia is a free AI shopping assistant that answers a simple question: "Should I buy this?" It shows users the best price and every available option in one click, scanning over 40,000 websites and indexing over 300 million secondhand items.
The sustainability angle is present but quiet. By surfacing price data alongside resale insights and secondhand products in one simple flow, Phia brings more sustainable options into the traditional consumer experience as a natural extension of it, rather than an exception.
That last part is the whole point.
Left: Phoebe Gates. Right: Sophia Kianni. Photographed by Zhamak Fullad.
The original thesis still stands
When we first covered Phia, we asked whether the sustainable marketing playbook needed rethinking. Specifically, whether leading with value, price, convenience, and ease, and letting the ethics follow quietly, was a more effective path to driving real behaviour change than waving the eco-flag upfront.
Phia's growth suggests yes.
One million users did not download this app because it helps the planet. They downloaded it because it helps them shop smarter and spend less. The secondhand integrations and resale suggestions are features, but the only pitch. And yet the cumulative effect of those features, at scale, is exactly what the sustainable fashion space has been trying to achieve through campaigns and messaging for years.
This is not a cynical observation. It is actually an optimistic one. It suggests that when sustainable behaviour is the path of least resistance, people take it.
What this means for purpose-led brands
Phia is not just a consumer app. It is a signal about where the discovery layer of fashion is heading.
As tools like Phia become part of how people find and evaluate products, the brands that will benefit most are the ones that have already invested in the infrastructure that these tools surface: resale availability, transparent pricing, secondhand integrations, and genuine sustainability credentials that hold up to data-level scrutiny rather than just good copy.
Greenwashing does not survive a tool that compares your product against 300 million secondhand alternatives in real time. What does survive is a product that is genuinely well made, fairly priced, and built to last.
For brands that have been doing the slow, unglamorous work of building that kind of integrity into their supply chain and their offer, this shift in the discovery landscape is good news. Your values are about to become structurally visible in ways that no campaign could achieve.
For brands that have been relying on sustainability language without the substance to back it up, the window is closing.
A closer look at their social media strategy
For a brand that has scaled to a million users in a year, Phia's social media operation is worth examining in detail. There are some genuinely smart decisions being made here that purpose-led brands of any size can learn from.
Focused platform presence
Phia is currently only active on Instagram and LinkedIn, with the vast majority of their energy going into Instagram, where they have accumulated 290,000 followers in under a year. That kind of growth on a single platform, for a brand that also manages a separate Instagram account for their podcast, is a deliberate choice rather than an oversight.
For a new brand building a team and sorting internal processes simultaneously, trying to maintain a quality presence across every platform at once is a fast track to inconsistency. Phia have gone all in on Instagram first and it shows in the quality and regularity of what they publish. The only question worth asking is when they plan to show up on TikTok, given that their messaging is heavily targeted at Gen Z and Millennials, the generations that essentially live there.
Five content series doing real work
What makes Phia's Instagram particularly interesting is that their content is not random. There are clear repeatable formats doing specific jobs across the marketing funnel.
Weekly Phia Trends
Once a week, they publish a post showing what is trending on the app. The first slide covers the general trend list across all products. Slides two and three break it down by city, showing what users in specific locations are searching for. The final slide lists the top brands being searched overall. They pair this with a ManyChat automation: comment the word "TREND" and you automatically receive the trending product list in your DMs. It is a genuinely smart use of automation to turn a content post into a conversion touchpoint.
Celebrity Closet Finds
They take red carpet moments from figures like Zendaya, Rosalía, Alex Cooper, and Chloë Shi, and use Phia to find either the exact pieces or similar alternatives at more accessible price points. It is an elegant format because it compresses the entire marketing funnel into a single post: the celebrity image creates reach and aspiration, the Phia comparison creates relevance and utility, and the accessible price creates the conversion impulse. All three phases of the marketing funnel at once.
Fashion Shows and Cultural Moments
Beyond individual celebrities, they use broader cultural moments as content opportunities. Press tours, red carpets, the Met Gala, any moment where fashion is being analysed publicly becomes an excuse for Phia to add their own lens. A recent example was breaking down Margot Robbie's looks during the Wuthering Heights press tour. It keeps them inside cultural conversations that their audience is already having.
Reach Campaigns
Every so often, they do something more IRL than social content. In their early days, they invited beta testers in New York City every week to review the app in person, give honest feedback, and help improve the user experience before scaling. Market research built into the community strategy. More recently they launched a Birkin giveaway: a bag valued between $20,000 and $35,000, with entries earned every time a new user downloads the app using your referral link. High stakes, high interest, and a clean conversion mechanic built in.
Podcast Clip Repurposing
The Burnouts, their podcast produced on Alex Cooper's Unwell Network, is more than a side project. By inviting successful entrepreneurs onto a weekly show, Phia gets two things simultaneously: visibility with the audiences of everyone they interview, and a library of high-quality clip content to repurpose across their platforms. Crucially, when clips appear on the Phia Instagram account, they are not there to promote the podcast. They are there to promote the app, using the credibility and pull of the podcast content as the vehicle. It is a content ecosystem rather than a content calendar, and the difference is significant.
A year ago, we said Phia was onto something. The growth confirms it.
The deeper lesson here is not really about Phia specifically. It is about what happens when a purpose-led product is marketed with enough confidence in its own value to not need the eco-label as a crutch.
What Phia has built on social media reflects the same philosophy as the product itself. Lead with what is useful, interesting, and entertaining. Let the values show up through the work rather than the copy. Build repeatable formats that serve your audience first and convert second. Grow one platform properly before stretching across five.
If you are building a sustainable brand and still leading every piece of content with your certifications and your carbon offsets, it might be worth asking whether the people you most want to reach are actually moved by that framing. Or whether they would respond better to content that is genuinely useful, and happens to reflect what you stand for.
Phia seems to know the answer.
We help purpose-led brands build social media strategies that are grounded in what they actually stand for. If that sounds like what you are looking for, get in touch here.
