Since square-inch analysis is derived from spatial measurements taken from published offers and actual sales results produced by those offers, it is normally undertaken at the conclusion of one promotional publication cycle, and before the beginning of the next. As a part of a larger discipline of marketing analytics, it might be seen as an "optional extra" that follows other effectiveness measurements and precedes another cycle of strategic planning. Applications Classic square-inch analysis was and still is used primarily by mail-order catalog publishers, because these vehicles contain multiple separate sales offers of varying size, and managers need a means of systematically subdividing aggregate publishing costs down to the individual item offer level. Printed offers in other formats (such as travel brochures, or magazine display ads) would also yield to this analysis. It has been suggested that square-inch analysis should play a role in website marketing analytics, but such use is not well documented. Obtaining Measurements For the simplest of merchandise sales offers, the rectangular area on a page occupied by an item's illustration, its descriptive copy, its order number and price can be measured by hand with a ruler and the square area calculated by the formula width (inches) x height (inches) = area (square inches). A simpler, less accurate measure can be obtained using fractional page sizes (e.g. quarter page, half page). Measurements are tabulated for each item offered on each page. In certain design presentations which display offer-specific content in two or more areas (such as an illustration and descriptive copy on facing pages), each separate area is measured and the areas are summed for that item in the tabulation. When an offer occupying a discrete area on a page comprises more than one item in a grouping, the collective area is subdivided by the number of items in the grouping and the apportionments are entered into the tabulation for each item. Non-offer areas such as front cover illustrations, postal address panels, indexes, order forms and editorial content are common in catalog designs. These areas can be treated individually in the same way as offers, or combined together with the space occupied by page margins, headlines, headers and footers and treated as "white space." A more conservative square-inch analysis proportionately subdivides the total of all "white space" and adds an apportionment to each item's offer area so that the cost of every square inch of space is accounted