Bank Transfer Day—Nov. 5—is now in the record books. By any measure, it must be considered a success.

After revising earlier numbers, CUNA now estimates 441,000 consumers joined credit unions last September and October. That’s about 75% of the membership growth for all of 2010—a remarkable influx of new members.

There’s a great temptation to demonize banks in all this. But banks are merely doing what banks are supposed to do—maximize profits to their shareholders.

Banks are for-profit entities and their business model is designed to maximize profits. It’s like putting a steak in front of a pit bull and being surprised when the dog devours it. It’s what pit bulls do—they eat meat. No one should be surprised when this happens. And no one should be surprised when banks try to maximize profits. It’s what they do.

During the past few months, banks have shown their true colors, and many consumers decided they didn’t particularly care for those colors. So consumers moved their accounts out of national banks and into local credit unions.

CUNA estimates credit unions opened about 400,000 new checking accounts in October, alone.

Now that credit unions have had this much-needed infusion of new members, the challenge becomes one of welcoming these newcomers and turning them into loyal members who sing the praises of financial cooperatives. The welcoming process is called “onboarding,” and credit unions have their work cut out for them.

“Onboarding new members is a critical process that begins when a member opens an account and continues through the first 60 to 90 days following the initial contact,” according to a 2010 Fiserv white paper, “Developing a Successful Onboarding Program to Drive Customer Loyalty and Profitability.”

Onboarding best practices underscore the importance of getting new members to sign up for online banking and online bill payment. Members who use these “sticky” online services are more likely to stay with your credit union for a long time and use more services while they’re there.

If the critical period is only two or three months after signing up a new member, the onboarding clock is ticking.