Abstract:
The purpose of this research was to develop and promote the marketing in Thai Yon Chonburi company which effects to purchase decision and behavior after purchasing. The sample population is the group of 400 customers who have bought the cars from the Thai Yon Chonburi company. The aim of this research is to study the personal factor which a person has for decision making to buy a car from Thai Yon Chonburi Company. Also to study the way to develop Sales Promotion of Thai Yon Chonburi company. The data collection used in this research is interview, analysis by using statistic program. The statistics used are Frequency, Percentage, Mean, Standard Deviation, independent samples t-test, one-way analysis of variance and Multiple Regression Analysis and Quality research it is an In-depth interview. 10 old customers in the customer group of the company will be interviewed. The old customer here means the customer who has bought the car here at least for connective 3 years. From the research found that: Most of the samples in the group are females who have the age between 21-30and most of them are single and graduated bachelor degree mostly. They work in the private company and earn the salary in each month between 30,000-40,000 Bath. Most of the samples use pickups. From the analysis of the data of the way to develop and promote the marketing in Thai Yon Chonburi Company which effects to car purchase decision and behavior after purchasing the car found that people have different personal factor. This lead to the different decision making of purchasing the car and the behavior after purchasing. The factors which are reason caused the people have different decisions are the age, education and salary. The factors which can cause the customers to buy the cars are the selling skill of the employees, the direct marketing and the advertisement. The Promotion factors which effects to car purchase decision and behavior after purchasing the car found that factor which effects to car purchase decision and behavior after purchasing the car are the selling skill of employees, promotion and direct marketing. The result of the interview from the customers who has bought the car here at least for connective 3 years found that the marketing activity which is important and cause the customers to buy the car is the advertisement, customer service, promotion and direct sell. Overall of the customers who gave interviews were very satisfied in the customer service and this makes them want to share their experiences here to others and all so make them want to return to buy the car here again.