Firstly, make sure you know your ideal or target customer and that is not just one that wants to buy your products or services! Know their age group, their interests, and hobbies, etc. Now that may seem a bit deep but if you look at your top 5 or 6 clients, you’ll most likely see some similarities. Once you know your target client, it makes the decision simple if you go by this formula. It must be useful and it must be memorable. If it’s not useful, it won’t be kept and will probably end up in the bin. And if it’s not memorable, well… what’s the point in doing it?