Internet book store advertising

Started with one trade campaign and a minimum budget.Even in the first week we went out to a little plus.They began to scale.Trade campaigns were divided into more marginal (with one rate limit) and less marginal (with the second rate limit).They also added a dynamic remarketing campaign.If we compare the last three weeks with the first, we have increased the number of real orders, lowered the conversion cost, increased the conversion coefficient and increased the percentage of the results.I further compare the first week (21 - 27 September 2020) with the last week (2 - 8 November 2020) at the time of the case written:
The number of orders increased 7 and a half times.Total profit increased by almost 10 (!)once .The marketing budget grew 6 times, and the real expenses spent on advertising - 4 times.The net profit (ROI) increased by 27 times!We continue further cooperation and look at the further scalability of advertising, hiring new employees, connecting new digital channels.