The venture capital firm, which also has investments in Betfair and LoveFilm, announced the funding last week.
My-wardrobe will roll out heavyweight direct marketing, CRM, social media, affiliate, paid search and PR activity, and live events, as part of its acquisition and retention efforts.
The retailer's marketing will continue to be handled in-house, but the brand has confirmed it is looking to appoint international agencies in the next 12 months, to ensure that campaigns in overseas markets are 'culturally specific'.
Although My-wardrobe has run CRM activity in the past, it intends to develop a more comprehensive programme to drive loyalty. This will be handled by CRM manager Katie Palmer.
Palmer joined in September 2009, having previously worked as a consultant for the Boots Advantage Card scheme.
Sarah Curran, founder and chief executive of the retailer, said: "My-wardrobe.com can attribute most of its growth to date to its PR efforts. The capital from the recent funding will [enable us to] significantly invest in both our marketing team and through-the-line activity."
She added: "Online is all about innovation. 'Spray and pray' email marketing is long dead; targeted emails with relevant content has been the order of the day for some time. The focus has to be on a one-to-one communication strategy, tailoring content to each customer.'
The Balderton investment will also enable the company to enhance its product offering and customer experience.
Launched in 2006, My-wardrobe is a destination for 'accessible luxury' fashion for men and women, selling items from more than 180 designer brands, including Dolce & Gabbana. Its target audience is more likely to be Net-a-Porter customers than those who shop at the traditionally more down-market ASOS.com.
My-wardrobe.com currently attracts 800,000 visitors a month, an increase of 110%, year on year. It also claims to have been the first etailer to launch click-to-buy video content, through My-tv.
IN MY VIEW - EXPERT COMMENT
Honor Westnedge, retail analyst, Verdict Research:
"Sitting firmly in the luxury sector, My-wardrobe competes directly with online player Net-a-Porter, as well as individual fashion brands.
"Investment in marketing is a great step for My-wardrobe to boost its presence and rival the likes of Net-a-Porter by expanding its customer base. It will also help swell its brand portfolio, which will boost its fashion credentials. Funding will also help it build on features such as My-tv, which is a great way of communicating with shoppers.
"The online clothing market is growing rapidly, leaving room for My-wardrobe to expand, while its international launch provides another avenue of growth."