I always tell my clients, only collect data that you're actually going to use. A corollary to that rule might be "If you're really going to use the data, you don't have to collect all the data yourself; consider third party sources for data you need."

It's not unusual for my clients to want to collect additional demographic data on their members, or to want to know what the universe of potential members is, or any of a number of other data-related issues pertaining to their members or market. Often the instinct is for staff to try and collect that data themselves. "We'll just put together a quick online survey to find out."

My suggestion is that before you try to do it yourself, see if a third party data service already has that data about your members. There are all kinds of sources for data about individuals and organizations, ranging from government census data to privately collected consumer demographic information. And this data is collected at both an individual and organization level, so both trade and professional associations can benefit.

As usual, the first rule applies: Don't collect data you're not going to use! But if you do have need for data you don't have, consider third party sources as an alternative to collecting the data yourself.