This guest blog is written by Hannah Fisher, a planner at iris Worldwide

One of the things I observe on a regular basis is how incredibly important friendship is to many of the adults I know. It's not uncommon for our friends to be closer to us than our family, to see more of our personal highs and lows.

But friendship isn't something marketers tend to examine very often in their day-to-day work. If you browse through the research portals we subscribe to, most mentions of 'friends' or 'friendship' are solely about social media behaviours and campaigns. I would argue that our industry doesn't understand the nature of friendship as deeply as it should.

Why should we care about friendship?

Today it seems to be a more significant relationship than ever, especially among Millennials: 34% of Brits aged 16-35 say having strong, dependable friendships is an important life goal. It actually ranks as a higher priority than having children or making a lot of money.[1]

Several socio-economic factors drive this. Firstly, we've only recently come out of an economic downturn, and the nation is yet to fully understand its post-Brexit future. Millennials have been coming of age and maturing in this climate, bearing some of its tougher realities from weaker employment and earning prospects to a lack of affordable housing. Friends who can empathise provide a valuable source of emotional support.

Financial pressures also make sharing more acceptable: living with friends to split the rent (or even a mortgage deposit), borrowing clothes, sharing Netflix accounts. This behaviour naturally draws people closer, driving honest conversations and deeper trust.

Secondly, Millennials and other generations are increasingly disrupting the traditional paths of adulthood: they are delaying marriage and parenthood to pursue other goals; they are getting divorced and re-entering the dating world at a later age; they are living longer. This creates more time and space for friendships.

Finally, ongoing urbanisation is drawing more people into cities, bringing them physically closer together and making it easier to socialise regularly.

It's also worth recognising the value friendship delivers at a purely emotional level. Psychological research into the factors influencing human happiness repeatedly shows that strong social relationships are absolutely key.

What's interesting about friendship?

The friendships we hold - the closest ones, at least - influence our outlook and behaviours. We also see our friends as a good benchmark for comparison because they're likely to have similar interests and represent things we value.

Friendships are unique relationships because they're voluntary. We choose to enter into them and by the same principle we can also choose to walk away from them; they're easier to leave behind than other relationships. This makes them precious. Friends are there because they genuinely want to be there.

How are friendship networks structured?

Friendships fall into three broad types.

The first type is our more immediate, 'real' friends. These are the friends that we like to see in person, if we can. We'll put time and effort into maintaining the relationships so we can talk to, depend on and enjoy each other. The anthropologist and psychologist Robin Dunbar suggests we have about 50 of these in total, with an inner circle of 15 friends, and another even tighter circle of around five best friends. Shared experience keeps these friendships close, because it allows people to form a shared language of inside jokes, references and gestures. Communicating in this way is a strong indication that a friendship will be long-lasting.[2]

The second type is casual friends and acquaintances. These are the connections we just want to keep ticking over. They strengthen our social currency: they make us appear more popular, they share cool ideas and stories, they hold ties to people or things we're interested in. According to Dunbar, we can only manage about 100 of these connections in a stable way, beyond our 50 'real' friends.

The third type is impersonal social relationships. These are the connections that we don't necessarily know outside of the internet or a specific physical place; they're built on common interests and people sharing information or content with each other.

What are marketers doing wrong, then?

There are two key issues here that are worth talking about.

Issue one: marketing misjudges the roles and dimensions of friendship. We do have a tendency to place our audience's social relationships into one, catch-all 'friends' bracket, and assume they interact with them all in the same way. Sometimes we just identify their friends as everyone in their Facebook or Instagram networks. But it's important to be sensitive to the different layers and dimensions in people's social groups - and to avoid downplaying the significance and strength of their closest friendships.

We also tend to undervalue friendship units in favour of the more traditional family unit. We often expect our audience to live with and centre their behaviours around family members. But almost a million UK households today are composed of unrelated adults (non-couples) living together.[3] And regardless of who they live with, people still enjoy spending moments with friends and generally aspire to do it more often.

Issue two: marketing values consumer-brand relationships over the relationships that exist naturally between consumers. This has become particularly apparent in the era of big data, which allows us to know so much about an individual and develop communications that are really personal and relevant to the moment they receive them. But the consumer-brand relationship is only as important as understanding the real, human relationships that consumers have with each other. These feel more intuitively personal and credible, and will almost always have the greater influence on their behaviour.

What can we learn?

Delve into your audience's friendships to unlock richer opportunities and insights, and to create more truthful human portrayals in your communications. Your brand doesn't need to belong to an obviously sociable category (such as beer or telecoms) to start an engaging conversation about friendship.

Recognise and work with the different levels of friendship in your audience's network, and consider ways your brand's product or service could better contribute to relevant friendship units - especially if everyone else is only talking to families.

Avoid placing too narrow a focus on your own relationship with an audience. Look and listen for opportunities to create a meaningful brand presence within the influence networks surrounding them, and aim to shape the culture of these networks over time.

[1] Leisure Habits of Millennials - UK - August 2015, Mintel

[2] Forecasting 'friends forever': A longitudinal investigation of sustained closeness between best friends, 2007, Andrew M. Ledbetter, Em Griffin, and Glenn G. Sparks

[3] Families and Households: 2015, ONS