ROI on discount offers

How far will discount offers go in triggering customer interest in an otherwise languid season? Fence sitters are clearly excitable set which can flow in your direction based on offers of Addons/Discounts. With several competing offers of add-ons & discounts from online retailers, the ROI keeps becoming more difficult to achieve. The going rate for a customer to be acquired in an online space is anywhere between USD 30 - 100 for a product sale price of between USD 100 - 500 with a gross-margin of between USD 5 - 50. So you need between 2 - 6 sales of each product to sometimes justify an initial customer acquired. In turn each customer may also provide 1-2 additional referrals, which will further help drive down the number of sales required to create a +ve ROI. The lesson perhaps is then to deliver a +ve brand experience which results in referrals and helps create a serial customer chain to lower your overall customer acquisition costs. Effective metrics on conversion / customer acquired can then help you in taking the decisions on what can be offered in terms of discounts.