Here you can find useful tips on how to scale your marketplace - https://clutch.co/app-developers/resources/how-to-scale-online-marketplace-app \

Hope it will help!

Hello!
Hope you have a nice day.
I will appreciate if you tell me what industry your marketplace relates to, it will help to give more specific advice.
In general, here are some tips for growing the audience of your marketplace.

Storytelling
Storytelling - this is what will build a strong community around your marketplace and saturate it with the ideas.

You can encourage your users to write blog posts about their experience renting a car and reward those with the best stories.

Partner with other businesses
A partnership is a great way to create a word of mouth for your product and promote it to a wider audience.

Scale the functionality
First of all, listen to your customers. Gather their feedbacks and, when growing your product, primarily add the features that your users request.

Organize events

Industry-related events are a great way to create a word of mouth for your business and unite people around the same idea.

Here are the most important factors for analyzing the efficiency of your marketplace.

Data for service providers

Number of buyers per day/month/year
Activity tracking per day/month/year
Customer liquidity (probability that a visit will lead to transaction)
Profit by countries/cities
Repeat purchase ratio
Revenue from buyers
Number of orders per buyer
Analysis of customer segments
Market conditions and trends

Data for marketplace owner

Number of listings on the marketplace
Listing growth rate
Provider liquidity (percentage of listings that lead to transactions)
Total sales value of the products or services sold via your marketplace
Tracking the steps user takes before buying
Customer acquisition cost (how much money you spend on new customer e.g. customer support or paid ads)
Seller growth rate
Revenue by location, market, acquisition channel or time
Take rate (percentage of the Gross Merchandise Value retained by your marketplace)