Jay, it's important to:

Specify service expectations. There are two aspects of service to consider: consulting and technical support. Consulting is an area of frequent user/vendor disconnect. Would you like advice on how to grow your list, improve your results and better serve your customers? If so, ask the company to spell out (in writing!) exactly when and how it will provide it. Don't settle for published white papers, user conferences or help on demand (although they are all useful). If you want someone invested in your business and your results, ask for a regular program review--and expect to pay for it.

Tech support is also critical to your success. Can you work with support that is available only during certain hours, or do you need 24/7 coverage? What kind of response time can you expect? Will you have a dedicated account team or be thrown into the pool? If your program is relatively simple, the pool may work just fine. If you have complicated applications, a dedicated team will give you better continuity. For the vendors who get to the in-person interview stage, ask for a live call to tech support.

Get the tech folks involved. Have your tech people talk to their tech people. Your top-level people need to evaluate what's under the hood and how well it will integrate with your existing systems. Also ask for current clients' tech staff references and have your people call them. If your high-level people bless the application, get the buy-in of the people who will use the tool on a day-to-day basis. Ask for an online/phone demo, preferably one that is "live" and comparable to your program. See if your e-mail application user can set up a sample campaign. This all-important "test drive" will narrow the field considerably.

Look forward. Given your growing list and growing business, you need an ESP that can grow with you. Ask your Web analytics vendor which ESPs it has worked with to integrate online and e-mail data. Does the ESP have a spam-scoring tool and/or one that shows how the e-mail will render in multiple e-mail platforms? How easy is it to integrate dynamic content? Can you track results at the user level as well as the campaign level? Beware of vendors who are adding features in planned updates or say they can adapt to your program--sometimes those new features take months or even years to launch.

Don't be penny-wise and program foolish. Every ESP has its own pricing method. Ask potential partners to price a specific scenario and include set-up, training, tech support and consulting as well as X e-mails sent over Y period of time. As you have seen with your current vendor, a low price is not always a bargain. E-mail is not a commodity; don't shave off that fraction of a penny at the expense of the larger picture.

Good luck!

The E-mail Diva