There is a major player now which has engaged themselves in keeping a watch of what people buy so that they can make their product the way people want it. This new player is the bank which is behind the debit or credit card.
Facebook and Google showing the ads on the basis of online behavior has been a thing for many years. Retailers like Amazon and Walgreen have also fed upon the transaction history of the user for the holding of their loyalty and influencing their future spending. Banks also want to now turn data which they have already about the spending habits of the customer into earn extra revenue by identification of customers and corresponding retailers. The banks are now becoming more and more aware that they may be sitting on what is a gold mine of data which may be used in the prediction or influencing of what customers spend. In the past, this data has been used mostly for protection from fraud.
The bank for example the eating habits of a person at one joint and then take money from another joint which offers similar cuisine and then give them an offer from that joint and earn money from both the joints by doing so.
The customization of retail had been begun by Wells Fargo for the individual customers on the 21st of November when it joined PNC, Bank of America, Chase and a few more smaller banks.
Experts feel that in the case of Google and Facebook they try to figure out the interests related to buying on the basis of searches or the web site visits, banks can be more influential as they have the exact data of where customers spend.