The B2B sector is growing dynamically like no other branch of e-commerce. More and more companies are considering transferring their B2B sales to the online world. Numerous benefits, such as lowering transaction costs, simple monitoring of buyers' activities or higher transparency of the sales process, influence the decision making. At this point, we are facing the choice of a SaaS platform, an Open Source or a dedicated platform. While SaaS platforms are quickly rejected, due to the low possibility of adapting to specific B2B processes, the decision weighs up to the end between open source platforms such as Magento and dedicated software. This article will try to explain why choosing a dedicated solution is a mistake.