How do I validate the idea that it can be something consumers and vendors want? How can I make this company work?
Before you launch your first product:
1. Talk with 10 consumers you think might buy. Confirm your assumptions, gain insight about buying preferences you didn't know before, and document the process. This doesn't need to be a formal survey. This could be conversational interviews.
2. Talk to 10 more consumers to validate the assumptions you gathered from the first 10 people you talked to.
3. Repeat the same process for your expected vendors. Note their key needs and desires. If there's a pattern plan to align your home decor marketplace features to fit those needs.
Most Viable Product
4. Launch a marketplace sample (MVP) to approach the needs and desires of the consumers and vendors. Don't confuse sell with install -- after launch, you may find that the needs play out very differently that when interviewed. Don't sink too much into your MVP. Consider the fees to build on WordPress or Shopify vs. something more templated like Etsy.com. Be financially and mentally/emotionally prepared to pivot your product or features for better alignment in your V1.
5. Pivot towards the most valuable problem/solution that the marketplace has demonstrated. At this point you will have pivoted your products, strategy, and/or model the 4th time. These pivots essentially setup your intangible "barrier to entry" and this type of socratic (hypothesis-driven) method is best practices for your future products.