Most financial institutions have profitable client relationships they've built over the years. They know how many products their customers own and keep customer contact records.

E-commerce strengthens this customer relationship further. It allows you to assess customer interests real-time. It frees up your time for face-to-face relationship-building with your best customers, while not neglecting the rest of your customers.

When we arrived at one regional bank, they had over 200,000 retail banking customers. Yet, they had 300 email addresses. And their strategy was “relationship banking.”

In four months, we grew the in-house list from 300 to 8,000 customers. How?

1. By getting the buy-in from the people who handle the customers
Most failed e-commerce projects originate at headquarters, where, after meetings with a handful of people, an announcement—through a memo or email—comes to the rest of the company about the “new” project. Customer Service was very reluctant to ask customers for their email address. Did we pay them to acquire addresses? No. We thought about it, but decided that treating online differently from other channels accorded it a status it didn't deserve. They had no problem confirming an address or phone number, but drew the line on an email account. Once service reps understood that e-commerce could free them up from the mundane calls that make up 80 percent of what they do all day, and allow them to focus on higher value activity—such as following up on sales leads that could potentially earn them more money—they thought nothing of it.

2. By not asking for more information than we really intended to use
A recent study lamented that most of the corporate probing we all experience was unnecessary, given that most companies never act on the information they extract from us.

Know in advance exactly what you intend to do with the information you're going to collect. Objectively prove to someone outside the project (or even better, outside your department) how knowing this information will increase profits.

3. By doing the best we can to not make the customer repeat the same information over and over
Most customers don't mind telling their banks the ages of their children if they think the bank will use the information to help them sort through the myriad college savings plans or make them aware of estate planning issues. But nothing irritates customers more than having to repeat the same information to each channel—the branch, call center, or web site, as if it's the first time they've ever heard the information.

Whichever financial institution holds your mortgage has hundreds of pieces of data on you. Yet, at most places, when you go to refinance the loan, they take your application as if it's the first time they've ever spoken to you.

4. By not casting too wide a net
Sweepstakes, contests, and site registrations can deliver a lot of email addresses. They capture non-customers too, however. Someone then has to sort through the addresses, separating customers from prospects. Without an in-house unique identifier such as an account number, it's difficult to differentiate each Mike Smith, Maria Lopez, or John Kim in your database.

Current customers are the most important e-mail addresses to collect, much more so than prospects. They'll be more receptive to your communications and likely to respond, since they're familiar with your company and its products.

5. By scrutinizing all the existing data in the company
In organizations larger than a few hundred people, employees come and go, unknown projects sprout up and wither before anyone discovers them, and multiple, redundant databases flourish.

Let the rest of the company know what you're doing—they may know of a quick way they can help you. A branch manager in one city may have started an email collection project six months ago just for her customers. The direct marketing coordinator may have done a list match with Experian for certain zip codes, asked for email match, then never did anything with the data.

None of this advice is complicated. It's the same set of common sense principles that we apply to our everyday business, but that become stifled when we apply our minds to e-commerce. If necessary, think of how you would handle the task if it were one you've confronted in your work for years. Adhering to the basics of business is often the best solution, even when it comes to high-technology projects.