No matter if you are creating a physical or webbased marketplace, the used car market is crowded. So you need to stand out.

So you need to explain exactly what value you are creating for the suppliers. Parameters could be:
- Convenience: Easy to set up a profile or deliver your car.
- Best price: You document that you will offer the best price
- Guarantee: You will take the car off their hands without any further discussion - they are free to go with money in their pocket, and you carry the risk.
- Best presentation of the car: Great location of the shop, best looking website, most traffic compared to competitors or some other KPI that would signal, that you will get them the most exposure.
- Referrals: People who trust you with regards to selling their car, will refer their friend, if you showed them a good experience. Pay for referrals from strategically chosed friends - f.ex. from mechanics, dealers of new cars, insurance companies or similar.

Those were just af few ideas to get you started. There are similar ideas for the buyer side. I will be happy to discuss both sides of your market in a call, if you want to set it up.

Good luck with your business!

Best regards
Kenneth

Agree with Kenneth that this is a crowded place. My suggestion would be to niche it down and focus on the supplier side accordingly. It could be based on:
- type of supplier (rental car agencies, seniors, married people looking to give-up their "fun" car for a kid-friendly car, etc.)
- type of car (could be brand, model, year, and/or category specific)
- serving geography (could be from a specific set of locations)
- and more

Hope this helps!

Hi, this is the classic chicken and egg question, but there are several considerations that will partly depend on your project. Normally it makes sense to focus on supply before demand, in the early days, but it's always a question of keeping a balance. And reacting to the needs of your users. If they are looking for 4x4s, get more of those. If they are looking for sports cars, get more of those. In all cases, remember that your suppliers deserve transparency and require honesty, there is no point in pretending you're bigger than you are. Good suppler relations are built one by one, they've got plenty of alternatives, you'll just have to do the leg work.

I designed and built several used car marketplaces, through my software company, learned some tips and tricks that I'd be happy to share on a call.