mediamarketplace.net
Newsletters, podcasts and niche sites are collectively enormous and individually too small to sell efficiently on their own. Connecting them to advertisers is the most interesting business this name supports.
Media buying and selling runs through marketplaces at every level: programmatic exchanges, direct inventory deals, sponsorship networks, and the fast-growing market for creator placements.
The name also suits an ad exchange, a rights and licensing exchange, or an inventory platform.
The .net reads as network, which is what a marketplace actually is, and the extension has a long history in advertising technology where nobody has ever cared about it.
Two common words, no hyphen, describing a business model rather than a product, which means the name survives whatever the platform ends up specialising in.
The name is listed for sale. Enquiries welcome.