When A “10″ Isn’t Perfect

Jun 25, 2007 9:18 PM  By

In scoring model files and ranking potential prospects on a scale of 1 to 10, sometimes 9 is better than 10. Maria Marsala Herlihy, senior vice president of strategic consulting and analytics for direct marketing firm KnowledgeBase Marketing, says you need to think like a computer programmer when assigning values.

Why? For Herlihy, this strategy takes up a consistent number of bytes. More important, it will mean less potential for your top decile to be mistaken for your lowest.

Speaking at DM Days in New York last week, Herlihy explained how a mailing campaign can be ruined if your 10 is mistaken for a 0 when the records are pulled, and why using deciles 0-9 is safer than using a scale of 1-10.

If you’re using 0-9 as your stored decile values – with 0 being the highest score and 10 being the lowest – and you want the top two deciles pulled, records would be pulled from deciles 0-1.

But if you’re using 1-10, with 1 being the highest score and 10 being the lowest, there’s a good chance the 10 will be mistaken as a 0, meaning you would actually have the best names and the worst names pulled instead.

Say you pulled 100,000 records from each of deciles 0 (with potential revenue of $87,000) and 1 (with a probable $65,250 coming in) for a mailing, the revenue would total $152,250. But if you’re using 1-10 as your decile scores, and the bottom decile is mistakes for the top, the potential loss in revenue could be critical.

In the example Herlihy gave, that would mean a possible $87,000 coming in from the top decile, and just $6,532 coming in from the bottom, or a projected revenue loss of $58,718 when compared to the 0-9 score. Herlihy says you need a consistent policy inhouse to assure you’re always pulling from the top, and not a combination of your best and worse scores.