Reduction of the conversion price by 30% and increase in sales x2 per year

Customer is a large store of car accessories. Conversion is a purchase through a basket or a phone call. The result is the growth of conversions almost twice and a drop in conversion price by a third.
The work performed:
Extension of Advertising and Assortment Format
- Implementing tracking of e-commerce with transfer of the value of closed transactions on requests received by phone using the Google Measurement Protocol
Regular advertising management.
In the cost of the project indicated the annual budget for services of the agency