SSPs (sell side)Private
OneTag
Fast-growing independent SSP and curation platform, with Italian roots.
London, UK · founded 2017 · onetag.com
What OneTag does
OneTag is an SSP connecting publishers and app developers to buyers, with a growing focus on curation: packaging inventory and data into ready-made deals for buyers.
It has grown through partnerships with DSPs and acquired Italian creative tech firm Aryel in 2026.
How it makes money
Share of ad spend transacted through its platform.
Where it meets invalid traffic
Screens supply for IVT and misrepresentation and supports transparency standards.
Products
- OneTag SSP
- OneTag curation