Have you said 'thank you' to your clients recently? No doubt, you'll have an order confirmation thank you email, or an email to thank your clients and throw in an extra discount. But, that's not what we mean, we're talking about literally saying 'thank you'.
Don't forget to thank your customers and contacts from time to time (without trying to sell them anything). You'll find that these simple and honest 'thank you's' strengthen your relationship in the long run.