Marketing Week (MW): Is retailing the main use for your digital operations?

Sue Leeson (SL): QVC is a retailer so that is our focus. As well as the website, we have a mobile application and red button interactivity on Sky, Virgin and Freeview. With the exception of Freeview, these are fully transactional with real-time stock updates.

However, our business is all about building customer relationships to stimulate long-term purchasing from our platforms, so we use digital technology to drive interactions with our customer base through blogs, forums, ratings and reviews.

Our differentiator is that we use video clips from our live broadcast online, trying to educate the customer by demonstrating the benefits and uses of a particular product. This aims to enhance the online customer experience.

Emma Jenkins (EJ): Digital is everywhere in our business. The UK leads the world in grocery ecommerce and with key players such as Tesco opening up their application programming interface and continuing to innovate, I have a huge amount of confidence in this sector. Brand building is also incredibly important to P&G. Earlier this year, we used social gaming on Facebook to support a key launch.

Malcolm Tucker (MT): Shop.com is a shopping engine. Our function is to help consumers browse, compare and buy products from the UK's leading online retail stores. We try to achieve brand building through developing our site, which is our product, and delivering a great service to our customers. Big, fancy offline branding activity hasn't delivered a return on investment for us.

Steve Purdham (SP): We7 provides an online music jukebox that lets consumers listen to any song or album in our catalogue (4 million at the moment) for free or buy full songs and full albums. The digital operation also allows us to syndicate music to other publishers such as NME, The Guardian, GQ and many others to build audience reach - again, providing value for potential brands. We combine retailing with a place to get over brand stories and ideas.

Darren Cox (DC): Nissan's online presence aims to build brand opinion before potential customers visit dealerships and physically get in touch with our products. With the established framework of franchise networks and complex distribution agreements, moving to online retailing is not straightforward.

Retailing from our website will come at some point, although the barriers are high. A car is an emotional purchase, a technical product and an investment. Most customers need to test and touch before they make a decision. Nissan had a very successful "toe in the water" with the GT-R supercar, which you could only pre-order online. We learned a lot of lessons from that exercise.

The next test for etailing for Nissan is our electric vehicle range. The cars represent a new way of moving, and we need a new way of selling.

MW: What is the biggest challenge in online retailing at the moment?

SP: We7 lets people listen to all the music they want for free via streaming and buy what they want in MP3 form. Many people ask: "Why buy if it's free?" By providing a "better than free" model, we aim to turn more people away from piracy into the legal net. The biggest challenge continues to be the fact that consumers' use of music is changing faster than the industry can understand; there are no single silver bullets in retailing anymore, just an infinite number of preferred ways of consumption depending on access and context.

MT: A big challenge is differentiating our brand and offering a unique selling point in an increasingly commoditised retail market. Low barriers to entry allow multiple versions of any business model to spring up overnight.