You can go for questionnaire method, if your loyalty program is digitally connected with your customer, you can go for on line survey also. Or you can also ask the customer directly if you have the mobile number of the customer.

thanks for suggestion sir. i went through BSNL office to get the mobile numbers but the organisation is not giving their valuable customer data.

suggest me if there is any online survey method to collect the data.

Thanks and Regrads

phani.

Article Exploring the key factors for establishing electronic commerce loyalty