Creating an online marketplace for tangible products certainly comes with its unique set of challenges, even if you have experience with intangible product marketplaces. Here are some key considerations:

1. Logistics and Shipping: With tangible products, you'll need to deal with the logistics of shipping, which includes choosing shipping carriers, calculating shipping costs, and ensuring timely delivery. Vendors may handle shipping themselves, or you might offer a fulfillment service where you take care of shipping and storage, similar to Amazon's FBA (Fulfillment by Amazon) program.

2. Quality Control: Ensuring the quality of physical products can be more complex than with digital ones. Establish quality control standards to maintain a consistent level of product quality across different vendors.

3. Returns and Refunds: Be prepared to handle returns and refunds, which can be more complicated with physical products. Define clear return policies and processes for both customers and vendors.

4. Inventory Management: You'll need to track and manage inventory levels to prevent overselling and ensure that products are in stock when customers place orders.

5. **Vendor Onboarding**: Vendors may need assistance in creating product listings, uploading images, and managing their accounts. Consider providing tools and support to simplify this process.

6. Payment Processing: Determine how you'll handle payments to vendors. Will you use a third-party payment gateway, or will you handle payments and disburse funds to vendors on their behalf?

7. Trust and Security: Building trust is crucial. Implement robust security measures to protect customer data and payment information. Also, establish trust mechanisms such as reviews and ratings to help customers make informed decisions.

8. Legal and Compliance: Comply with legal and regulatory requirements, which can vary depending on your location and the types of products being sold. This may include sales tax, product liability, and intellectual property issues.

9. Customer Support: Provide customer support for inquiries, issues, and disputes. A robust support system can help maintain customer satisfaction.

10. Scalability: Consider how your platform will scale as you onboard more vendors and customers. Ensure that your infrastructure can handle increased traffic and data.

11. Marketing and Promotion: Attracting both vendors and customers will be critical. A well-thought-out marketing strategy can help you grow your marketplace.

As for Amazon's model, you're correct that they allow vendors to fulfill their own products, and they take care of the order process. However, Amazon also offers fulfillment services for vendors who want them. Your approach can be similar, offering flexibility to your vendors.

If you're looking for professional help in building your online marketplace, you might want to consider checking out services like Cleveroad's Retail Solutions: https://www.cleveroad.com/industries/retail/. They can provide valuable expertise and assistance in developing and scaling your marketplace.

Best of luck with your venture into the world of tangible product marketplaces!