One by AOL
| Company type | Subsidiary |
|---|---|
| Industry | Mobile advertising & Monetization |
| Defunct | September 10, 2018 |
| Headquarters | Baltimore, Maryland, USA |
Area served | Worldwide |
Key people | Tim Mahlman (President) Seth Demsey (CTO) |
Number of employees | 601 (January 23, 2014) |
| Parent | AOL |
| Website | www.onebyaol.com |
One by AOL, formerly known as Millennial Media, was an advertising company that places display ads on mobile devices (mobile marketing).