When it comes to buying clothing, for most of us popping into the local Oxfam store is the exception rather than the rule. Why buy second-hand when brand new clothing from high street retailers is increasingly affordable?

Not only is the high street catering to our desire for seasonal wardrobe refreshes, but the evolution of one-day delivery and easy returns means keeping your wardrobe in touch with the catwalk is suddenly far more feasible (assuming a sense of style somewhat greater than my own).

The problem is the exponential increase in online ordering and affordability over recent years has created a global bi-product. Clothing has become disposable. In fact, more than half of fast-fashion items are thrown away in less than a year, according to McKinsey’s State of Fashion report last year.

Fast fashion is now a huge environmental problem. Water pollution, toxic chemical use and textile waste are just some of the costs to the environment that result from our love of fast fashion. But consumer awareness around the environmental impact of fashion is still relatively low.

This is largely a product of the fractured nature of eco-friendly alternatives. Perhaps the biggest champion of eco platforms is Shopify. Almost 400,000 merchants use Shopify to power their e-commerce. But as Timothy Dann-Barrick, admin of Shopify Entrepreneurs surmises - "people who are not as focused on the environment probably are a little more business minded."

This is the opportunity ambitious brands like 'Depop' have seized by the horns. Established in 2011, the site offers its 10 million users a blend of eBay-style trading for second-hand clothes with Instagram-style posting.

The site astutely acknowledges shoppers are factoring personal values into their purchase decisions. It's one of the reasons why influencer marketing has become such a prevalent part of western economies. Done well, these social media figures help propagate the ethical positioning of challenger brands.

Beyond purely sustainable advantages, Depop vendors also pride themselves of the quality of the items being exchanged through the site.

The challenge facing progressive businesses such as Depop is how they can win the trust of consumers accustomed to the safety of buying new. Depop is getting around this by playing to the same strengths of successful fashion brands. They are encouraging as much customer content as they can - reviews, ratings, testimonials - all of which help customers paint a clear picture of what they're buying.

Depop's natural advantage is its choice of a highly visual platform. Images of every single bespoke item are already loaded on to the site by the vendor.

It's a powerful and potentially highly disruptive arrival in the retail industry. By adopting the strategies that work for the big brands, the traction Depop is getting at the moment is capable of raising sustainable alternatives - through networks such as Shopify - into the mainstream.

Should this manifest, it's important the big names of fashion are ready to respond. If consumers feel they can buy great products in a sustainable way we could see attitudes to fast fashion start to evolve.