This is mostly a summary of this McKinsey study (https://www.mckinsey.com/business-functions/marketing-and-sales/our-insights/seven-rules-to-crack-the-code-on-revenue-synergies-in-ma)
“When we carried out a survey of 200 seasoned M&A executives from ten industries, the majority reported that their company had fallen short of its aspiration for revenue synergies, with an average gap of 23 percent between goal and attainment”.
Furthermore, revenue synergies take, on average, 5 years to come through.
Prasad Capital 