The most expensive architectural mistake in B2B commerce is the assumption that it's just B2C with a login page. It's not. The domains are fundamentally different, and treating them as equivalent produces systems that fight their users at every turn.
Where the models diverge
In B2C, pricing is simple: a product has a price, maybe with a sale price. In B2B distribution, pricing is a negotiation surface. Customer-specific pricing, contract pricing, volume breaks, matrix pricing, promotional pricing — these aren't edge cases, they're the core model. If your commerce platform can't handle this natively, you'll spend your life building workarounds.
Catalog visibility is another divergence. B2C shows everything to everyone. B2B distributors need customer-specific catalogs, restricted products, approval workflows, and account hierarchies where a purchasing manager in one branch can't see another branch's negotiated pricing.
The checkout problem
B2C checkout is optimized for impulse. B2B checkout is a workflow. Purchase orders, approval chains, split shipments, will-call vs. delivery, tax exemptions, credit terms — these are table-stakes requirements, not enhancements.
Platforms designed for B2C treat these as extensions. The result is a Frankenstein checkout that confuses buyers and creates operational chaos for your customer service team.
What this means for platform decisions
When evaluating commerce platforms for B2B, the first question isn't about features. It's about the data model. Does the platform's core data model understand B2B concepts natively, or are they layered on top of a consumer model?
If pricing, accounts, and ordering are afterthoughts in the schema, no amount of customization will make it feel right. You'll be fighting the platform instead of building on it.
The right platform for B2B distribution isn't the one with the best marketing site. It's the one whose data model matches your domain.