It is always conceivable, though it may scarcely seem probable, that these incidents of increased pressure of competition in business traffic might eventually take up all the slack, and leave no net margin of product over what is available under the less favorable conditions of industry that prevail today; more particularly when this increased competition for business gains is backed by an increased pressure of competitive spending for purposes of a reputable appearance. All this applies in retail trade and in such lines of industry and public service as partakes of the nature of retail trade, in the respect that salesmanship and the costs of salesmanship enter into their case in an appreciable measure; this is an extensive field, it is true, and incontinently growing more extensive with the later changes in the customary methods of marketing products; but it is by no means anything like the whole domain of industrial business, and by no means a field in which business is carried on without interference of a higher control from outside its own immediate limits. All this generously large and highly expensive and profitable field of trade and of trade-like industry, in which the businessmen in charge deal somewhat directly with a large body of customers, is always subject to limitations imposed by the condition of the market; and the condition of the market is in part not under the control of these businessmen, but is also in part controlled by large concerns in the background; which in their turn are after all also not precisely free agents; in fact not much more so than their cousins in the retail trade, being confined in all their motions by the constraint of the price-system that dominates the whole and gathers them all in its impersonal and inexorable net. There is a colloquial saying among businessmen, that they are not doing business for their health; which being interpreted means that they are doing business for a price. It is out of a discrepancy in price, between purchase and sale, or between transactions which come to the same result as purchase and sale, that the gains of business are drawn; and it is in terms of price that these gains are rated, amassed and funded. It is necessary, for a business concern to achieve a favorable balance in terms of price; and the larger the balance in terms of price the more successful the enterprise. Such a balance can not be achieved except by due regard to the conditions of the market, to the effect that dealings must not go on beyond what will yield a favorable balance in terms of price between income and outgo. As has already been remarked above, the prescriptive and indispensable recourse in all this conduct of business is sabotage, limitation of supply to bring a remunerative price result.