Many companies still don't understand the youth market, he says. Young people are nimble; they have lots of interests and make decisions quickly. "Some industries, like banking, are corporate and not at all nimble. You find companies that are actually uncomfortable marketing to the young."
HDI helps brands connect with people aged three to 23. The upper age, theoretically, is when people leave university, get their first jobs and become "adult".
Youth marketing, he explains, is less about putting across messages than starting dialogues. Much of the agency's work is experiential, allowing young consumers to engage and interact with products. Today's youth are growing up in an online, connected age where consumers, rather than marketers, control brand image.
Levin says the nature of modern SA makes for some very different markets. HDI's programmes connect with 4m learners annually at 6000 schools. At township schools, even those from the poorest families aspire to Gucci, Breitling and the other luxury brands they see on TV or in magazines. "Township children have the same aspirations as those in Sandton." In rural schools, by contrast, "most children are underguided and underambitious". Levin says: "They can't see themselves at 21 and beyond. There is no ambition or aspiration."
Levin describes HDI as Africa's largest youth marketing company. Some of SA's biggest brands use it to connect them with young people. Longstanding clients include Procter & Gamble, Pick n Pay, Reckitt Benckiser and GlaxoSmithKline. New accounts in the past year include Danone, Bakers, Nestlé Smarties and Spur.
But there's also a lot of social messaging.
There is clearly plenty of scope for growth in the youth marketing sector. After 16 years in business, HDI "is still on a high-growth trajectory". Revenue grew 27% last year and Levin says the size of the business has doubled in the past four years.
South Africans up to the age of 23 spend over R104bn annually. "It's a significant market, not a fringe one," says Levin. "Every year there is a greater realisation of its importance."