Lifetime client value is amount of money your client is likely
to spend with you during the period of time he is your client.

For example, if a client spends on average $700 each time he purchases your product or service, and he/she on average purchases 3 times per year, and the average client remains your client for 5 years, then the lifetime client value is
$700 X 3 X 5 = $10,500.

How can this help you? Once you realize that every new client is worth to you $10,500 instead of $700, you will better determine how much you can spend on client acquisition and how well you should treat your clients.