In marketing speak, quite often you will come across the term 'Test & Measure' and I would advocate this with all your marketing activity. What is the point of wasting your resources in terms of time and money on activities that do not work.
You may have undertaken your research and identified that a certain type of marketing would be best for your target market or customer. However I would encourage you to test other marketing ideas as well and not leave all your eggs in one basket.
In addition, when testing, there are two key thoughts to remember:
1) Test small first - for example if you decide to undertake a direct mail campaign distribution of 30,000 prospects, then test your message and contact list with a small part of this total number. For example, testing to 2,000 to identify your message and market is not right will save a lot of wasted money.
2) Split testing. If we take our direct mail example, then you may wish to test a different message, material or idea to to say 1000 than the other 1000. Then see which generates the best response and roll this out on mass.
Testing with Online marketing will be much quicker, sometimes instant, so if you are marketing with offline activity such as direct mail or telephone calls, then you need to be patient to measure the true results.
If you are marketing in many different activities, then ensure you have a way of measuring the enquiry and which method truly generated the response.