Imagine a marketing department asking for more money to conduct a direct-mail campaign and their only justification was that marketing is a critical business advantage. Now contrast that with an argument that showed that in a previous direct-mail campaign the response rate of 3% was more than twice the industry average and was achieved from testing a sample of the campaign on customers. The test led to a more effective message and ultimately in an additional $100k in sales.

If a usability manager asked for money to conduct a usability test based only on the argument that usability is critical for business then you’re making the same argument. Contrast that with an argument that showed the last usability test reduced transaction time by 50% and reduced check-out abandonment rate by 20%. It was achieved from fixing problems with button labeling and placement and led to an additional $100k in sales over a year.

Advertisers quantify the effectiveness of ads.
Marketers quantify the effectiveness of campaigns and promotions.

Of course, not all advertising campaigns and promotions are tracked. Just being in marketing or advertising doesn’t mean you magically quantify things. Quantifying inputs and tracking results to inputs is what separates inefficient marketing and advertising endeavors from efficient ones.

Quantifying usability means making better decisions about usability data by tracking usability efforts to results. Quantifying the reduction in problems, the increases in efficiency and the increases in satisfaction from design changes will lead to better business decisions.  Relying on qualitative problem lists and intuition and hoping the efforts are paying off is like marketing campaigns with no tracking mechanisms.  For more information on quantifying your usability efforts, see the report on quantitative usability testing.