Speaking at the Genesys user conference G-Force in Melbourne, Australia Wednesday, Brooks said customer loyalty can increase revenue by 25 percent to 100 percent.

Genesys research has found that 1 percent of incoming calls in call centers generates up to 50 percent of revenue.

Brooks said call centers must improve service agent conditions, their objectives and staff levels to eliminate negative service 'exceptions'.

He said managers must focus on eliminating the 'one-in-five' poor service exceptions, which 73 percent of customers say are caused by long waiting times.

"Contact center managers should assess agent engagement by measuring strengths and weaknesses and strategies against revenue.