这种形式的商业需求，不只是一个知识背景扣除以及抵补。

This form of business does not just demand a debiting and a crediting knowledge background.

出售额外的商品获得的收益至少要能抵补花费的额外的销售成本。

The extra items sold must make enough profit at least to cover the cost of the additional time spent in selling them.

目前该网站的广告销售收入已经足以抵补开支，包括给两名全职员工支付薪水。

Ad sales cover the site's expenses, including the salaries of two full-time employees.