One important difference between B$2$B and B$2$C e$-$commerce systems that primarily affects the second stage of the multistage model for

invoicing buyers after shipping products is much less common with B$2$B systems

buyers typically begin their research at preferred suppliers' Web sites with $R2C$ systems

support for price and delivery negotiation is usually not essential with B$2$C systems

retaining customer information for later reference is less important with B$2$B systems