In my opinion all activities in sales and marketing, are itself small process, hence six sigma is applicable at stage of sales and marketing
1.Presales - identification of potential customer
.. custering / segmentation
.. prediction of who will buy and who will not ....maltivariate analysis, Multiple logistic regression
2. Response to time query by potential customers
3. Prediction of customer will reorder or not
4. Identification of customers needs and wants
DOE/ KANO modeling
5. Lean concept _ minimum documents ftom customer ...autimation _ JIO case _ two step verification using Addhar
6. Lead time predection after order from customer
7. MSA of sales engineer..quotation given by engineer/ manager
8. Response time after sales calls from customer
9. Error reduction in filling order from
10. Days to invoice after delivery