Some form controls automatically have labels associated with them (press buttons) while most do not (text fields, checkboxes and radio buttons, and menus). For those controls that have implicit labels, user agents should use the value of the value attribute as the label string. the label element is used to specify labels for controls that do not have implicit labels.
This is an excellent usability feature for visitors to your forms. Using the label element allows the user to click on the text associated with the form control instead of having to click the radio button, check box, select box, etc.
In interface design they call it improved targeting, and it can help reduce the risk of repetitive stress injuries (RSI). tedster 2004-01-25
One label element and one ID per form control.
<input name="action" type="radio" value="title" id="name"> <label for="name">Form control text.</label>
27 additional bytes (+ ID Name and label Name) to add a noticeable usability function. Very minimal html code required for this feature.