BankFinancial, a Chicago-area banking chain, was sure that the best prospects for its high-balance checking account were people age 55 and older.

That was an accurate guess.

But finding them was a challenge until the bank employed Clementine, a data-mining workbench from SPSS, a predictive analytics software vendor that's also based in Chicago.

And then it discovered something when planning its first 2,500-piece test to customers: That certain people under 25 — those who had received settlements or inheritances — were fine prospects for the product as well.

Thanks to that newfound predictive ability, BankFinancial pulled a 6.77% response rate, according to Matthew Jacobs, market research analyst for the firm.

But that was only one part of a massive effort to make the bank more competitive in its commodity business, according to Jacobs' boss, assistant vice president for database marketing William Connerty.

“Eight years ago, Excel was the only analytical tool we had,” said Connerty, speaking last month at the National Center for Database Marketing conference in Orlando, FL.

That wasn't good enough for Chicago's third-largest thrift. The bank, which has 16 branches and $1.6 billion in assets, jumped into predictive analytics, “an evolving process” that continues to this day.

The first thing BankFinancial had to do was extract transaction data. It also had to identify households (it serves 57,000 and has a total of 71,000 customers), append demographic data, and gender- and geo-code.

The goal was to predict “who's likely to buy and churn,” Connerty said.

That wasn't all. The bank has tried everything from focus groups to lateral-thinking technology. Mapping has been useful not only in picking sites for branches, but for targeting direct mail, Connerty continued.

When Clementine, a system that starts at $75,000, was deployed roughly two and a half years ago, it was immediately put to work locating customers for the $10,000-plus checking accounts.

The metrics were impressive, and they continued to be during the rollout. The bank is now mailing 10,000 pieces a year for the product.

The persons chosen via Clementine generate 9.4% more income and a 9% higher balance per account than other customers. And 4.3% of the total deposit dollars for that account type have been raised by the campaign, according to Jacobs.

And it's no wonder. The total household deposit balances for all the customers reached is $123 million.