An example of marketing economies of scale at work would be the capability of the generator companies to lower the prices whenever deciding on non reusable fuel contracts. Similarly the large retailers like Marks and Spencer and House of Fraser I the UK market also enjoy monopolistic power as their purchase power is higher in the market relative to their competitors.
The example for the network economies of scale is the adoption of a common currency and the communication technology by the multinational corporations which operate ion more than one country. The increased scale of their operations reduces the cost of acquiring the technology. The phenomenon of eCommerce is basically the exploitation of the network economies of scale which has been best put in place by the Ebay Company.