In regards to customers, most buyer-seller relationships are based on?
1.Product/service quality as defined by customer needs?
2.reducing the customer's total procurement costs
3.personal relationship
4.reciprocity

It depends on the product

4. Is typical when there is a symbiotic relationship (like client and
supplier need each other)

3. Is a result of a successful 4) - or a sales girl with short skirts

2. Is ambivalent - it could be a switch from an expensive alternative supplier
   - it has been known for suppliers to be embarrassed by overcharging clients

1. Sell them crud and run away - or sell them stuff that makes them stay.

Oddly, 'marketing' could learn a lot from contemporary drug dealing
- that would make an interesting thesis ...