This research aims to study a model of marketing strategic towards generationmillennials customers’ buying decision using food delivery application and to present model of marketing strategic towards generationmillennials customers’ buying decision using food delivery application. The mixed methods approaches of quantitative and qualitative research methods were used. In qualitative research method using in-depth interviews with 11 respondents and quantitative research in which questionnaire was used as an instrument to collect data from 400 populations of generation millennials customer living in Bangkok who order foods through food delivery application. Statistics for data analysis included frequency percentage average standard deviation exploratory factor analysis (EFA) The results indicated that most of the respondents were women with a bachelorsdegree who had a career as private company employees and an average monthly income of 18000 – 25000 bahts use Grab application the most use less than once week there are a total of 2 orders per order choose order the most street food average 100 - 350 Baht cost per time order food in the evening (17.01-22.00 p.m.) order food to eat at accommodation most order food to eat with friends reason for ordering a delivery is that it is comfortable from out going by self choose to pay by cash and consumers think that all of the factors are important in deciding to order food from restaurants through the Delivery Application application at high level. Results analysis of factors affecting generation millennials customers’ decision making to order from food delivery application be classified into eight factor as 1) easy to user experience strategy 2) goods value and price strategy 3) physical evidence and presentation strategy 4) strategies for brand awareness 5) accuracy and complete strategy 6) restaurants management system strategy 7) sales promotion strategy 8) new product development strategy.

The purposes of this research are 1) to study the demographic characteristics and behavior in purchasing via line application and 2) to compare the level of satisfaction in purchasing via line application for an open chat consumer group Kheha Thanee 4 Village Bangkok. This study applied quantitative methods and the research instrument was an online questionnaire. The sample group of this study consisted of 306 consumers members of the open chat consumer group Kheha Thanee 4 Village Bangkok. The data were analyzed by frequency percentage mean standard deviation and the researcher tested hypothesis with T Test and One Way ANOVA. The research findings were as follows:

The purpose of the study on decision making to buy Arowana fish online was to investigate the customers’ purchasing behavior on Arowana fish through online selling channels. This is a survey research study and the tools used in the study were the online surves generated from the review of relevant research papers. The data were analyzed from 311 customers using frequency mean standard deviation K-Mean clustering grouping. The research result revealed that most of the customers were males between 31-40 years old with buying reasons for the beauty of the fish called Malaysian Golden Arowana with the price between 5000 - 10000 baht. According to the study on the factors affecting the decision to buy Arowana fish via the online channel the respondents had a high level of decisionmaking on marketing mix in all aspects including the product physical environment price distribution channel process marketing promotion and person. It was found that male behavior was different from the female in terms of the price to purchase which was less than 5000 baht. It was also found that they were from all ages with the same reasons to buy fish for its beauty. However the fish species purchased and prices varied according to the age range. The respondents who were less than 20 years old bought high back Arowana fish for the price of lower than 5000 baht as well as those from 20 to 30 years old. The customers who were 31 - 40 41-50 51-60 and over 60 years old bought golden Malaysian Arowana on the price ranges from lower than 5000-10000 baht 20000 baht or more 5000 baht and lower and 10000 - 20000 baht respectively. By segmenting customers by means of K-Mean Clustering it was found that in Group 1 the majority were males aged 41- to 50 years old with the reasons to buy for the beauty of golden Malaysian Arowana fish with the price of 5000 - 10000 baht. Group 2 was mainly males 21 - 30 years old with the reasons to buy for the beauty of golden Malaysian Arowana fish with the price of lower than 5000 baht. Group 3 was mainly males who were 21 to 30 years old with the reasons to buy for the beauty of golden Malaysian Arowana fish with the price of less than 5000 baht. The fourth group was all males aged from 31 to 40 years old with the reasons to buy for the beauty of golden Malaysian Arowana fish with the price of 5000 - 10000

Online marketing is marketing in the online media. The main objective is to make known the increase by different methods to sales the goods and services which present our products to the public by social media. So that others can recognize and generate interest then they use services or purchase our products in the most. The Online Marketing is sends a message to mass recipients. In todays society we can classified consumers into three generation; Generation X generation Y and generation Z when we know the characteristics of the recipients marketer will send the message with social media to correctly understanding and more convenient. This is the duty of the marketer to understand the behavior of Generation XYZ and creation to consumer acceptance Adoption of Innovation and Technology Innovation diffusion and adoption of innovation. In order to plan for online marketing success under the terms of the innovation itself.