Johannesburg — NOT all the best films make it to the big screen. Not all the best restaurants get discovered. And not all the best marketing or product ideas see the light of day.

Why are there not more ventures like Pret A Manger and FedEx? New products like Innocent Smoothies and iMacs? Or marketing campaigns like those for the Mini?

It is because the process of invention often weeds out the best concepts. In my experience, five practices kill off promising concepts too soon.

Killer number one is falling in love with your product and ignoring second-hand insults. After spending years perfecting a product, some marketers become so enamoured with it that they cannot see its flaws.

Years ago, Synectics ran live consumer sessions so a confectionery company could get direct market feedback. A teenager said to a marketing vice-president: "You know, this brand wrapper looks like a piece of crap."

The executive immediately asked his market research manager how this could have slipped through their research.

The research manager told him the teenager's reaction had been expressed in every market research report the company had commissioned over the past five years. Until a live customer confronted executives with it, they conveniently ignored it. Changing the wrapper and creating new adverts ignited sales.

Killer number two is letting a focus group rip into it. While marketers must always strongly consider consumer feedback, some take it too far, especially if they let a focus group cast the final vote.

It is human nature to find fault. Many focus groups begin by tearing apart a new concept, and group dynamics sees each consumer then finding a bigger problem than the last. When the group moderator surfaces the pluses, the tone has been set and the group has nothing left to say. Concept killed.

Killer three is assuming the customer is always right. Many sophisticated marketers rely on consumer screening tests to convince the organisation to fund a new product or the latest marketing concept.

The numbers don't lie, is their belief, and if the effort bombs, their defence is ready. The problem with asking consumers hard questions about a new concept is that they will often shoot down an idea they cannot relate to.

In the early 1990s, the initial reaction by many UK consumers to cellphone text messaging was: "Why would you want to tap messages into your phone?" The product caught on slowly until people discovered the latent potential of text messaging: avoiding live conversations but getting the message through.

Today more than 70% of UK consumers use text messaging and send more than 1,6-billion messages a month or 20% of telecom revenue.

Killer four. Strangling it with a funnel, onion or any other brand framework. The most savvy marketers use frameworks (sometimes referred to as funnels or onions) to ensure new products and marketing campaigns do not erode the chosen brand.

Such frameworks pinpoint the qualities any new product or campaign must have, how it should be marketed, and so on. There are 1001 ways to destroy a powerful brand, so such frameworks are invaluable until marketers and product developers need blockbuster ideas.

Such frameworks can strangle radical new ideas. To make sure a bold new idea passes the framework test, the team begins to chip the edges off the concept. Eventually, it becomes so emasculated it never excites anyone. Big ideas cannot grow in small boxes.

Killer five is regarding yourself as the authority. Pure arrogance prevents many marketers from considering ideas offered by nonexperts. However, many great ideas come from supposedly "ignorant" sources.

The idea for the first Polaroid camera came not from a scientist in Edwin Land's laboratory, but rather from his three-year-old daughter. On holiday at the Grand Canyon in 1943, she asked why she could not see the picture he had just taken. His light bulb went off.

In a consumer session a computer company held several years ago, one consumer wished for a computer that would look attractive in her home. Company attendees laughed so hard the consumers could hear them on the other side of the wall. This happens when marketers think they are the product experts and everyone else is not, and is especially strident in market research settings, which cast consumers as "ants" to be observed.

The first and last practices stem from arrogance; the middle three from risk aversion. Finding a middle ground between the two extremes and ending practices that murder ideas mean marketers can take a lead in creating the next Mini, Smoothie or Pret A Manger.

David Walker is a partner at innovation consultancy Synectics.