After defining the Marketing Mix in our 3rd article
We found that the Marketing Mix & the 4Ps are focused only on the seller point of view neglecting the customer point of view, which made a gap between the seller & buyer.
We “as marketeers” have to develop our Marketing Mix from the 4Ps to the 4Cs
(Customer value – Cost – Convenience – Communication)
1- As we said before customer want to buy Value or a solution to their problems. so you have to sell a customer value not just a Product.
2- Also you shouldn’t Price your product/service on a Cost Plus strategy which calculate your price according to the accumulation of all costs you afford + the profit margin, But you have to price your product/service according to the satisfying Cost your targeted customer can afford to purchase your product !
Note: The satisfying cost doesn’t mean low prices, Apple products are premium-priced. Perhaps that’s the key, as the cost to satisfy, for a brand like Apple, has to be higher than the competitors, to contribute towards the brand’s DNA as a luxury brand.
3- You shouldn’t Place your product only in the available places,
but in the Convenient places for your targeted customer to reach & buy it without any complaints from how far the selling point’s places are !
4- You have to consider the Communication instead of Promotion. Promotion is manipulative !
It’s from the seller. Communication requires a give and take between the buyer and seller (that’s nicer). Be creative and you can make any advertising “interactive”. Use phone numbers, your web site address, etc. to help here. And listen to your customers when they are “with” you.
For that reason, nowadays all marketeers are using the social media as a main marketing channel or main “Communication channel” as it’s a very two way communication channel.
Hurry up and change your marketing mix from the 4Ps to the 4Cs and tell us how that made a difference into your market 
😉
Btw: 4Cs theory is designed by: Lauterborn, 1990.