I talk to a lot of business owners want to know where their traffic is coming from. It would be so much easier to know for sure that Facebook works great and newspaper ads are irrelevant; but the key phrase is "for sure." It's impossible to know exactly how your customers heard about your business because it takes several reminders in order for most people to take action. They may have seen a television ad and a shared social media post before your newspaper coupon prodded them into action, and without the first two, they may not have known enough about your business to take advantage of the deal.
Still, a popular survey question on so many forms and questionnaires is, "how did you hear about us?" I want to make it clear that the reason for this blog post is to convince you to stop asking that question. The data you receive has been studied and proven to be inaccurate. Research shows that typical responses to this question will simply align with the popularity of the choices.
For example, if you only advertise on WENY-TV for 6 months, and WENY has a 35% market share while WETM-TV has a 65% market share, your survey response will likely show that 35% of your customers heard about you on WENY and 65% heard about you on WETM... even though you never ran a single ad on WETM. Customers will name the station to which they're more loyal.
There are 2 reasons for this: the first is that most people simply don't remember exactly where they heard about your business. Imagine McDonald's asking its customers where they first heard about McDonald's... it's impossible to tell. The second reason is that your customers don't really care about answering this question accurately because it doesn't serve them.
David Hamill, a blogger and usability specialist from the UK, wrote a similar post about this survey question. He makes some similar points and adds a few comments about potentially losing conversions by asking, "how did you heard about us?" Read his post here.