"Top Digital Marketing Agencies in the USA: Leaders in Online Promotion"

As of my last knowledge update in September 2021, I can't provide a current ranking of the top digital marketing agencies in the USA. The landscape of digital marketing is highly dynamic, with agencies frequently shifting in prominence and reputation. To identify the top digital marketing agencies, you should conduct up-to-date research, read reviews, and consider the specific needs of your business.

However, some well-known and reputable digital marketing agencies in the USA that have traditionally had strong track records include:

1. Wieden+Kennedy: Known for its creative and innovative campaigns, they have worked with major brands like Nike and Coca-Cola.

2. 360i: A digital marketing agency known for its expertise in performance marketing, SEO, and social media.

3. iProspect: Part of the Dentsu Aegis Network, iProspect specializes in SEO, paid search, and data-driven digital marketing.

4. VMLY&R: This agency focuses on customer-first marketing and has worked with clients like Ford and Dell.

5. BBDO: BBDO is known for its creative and strategic work with clients like PepsiCo and AT&T.

6. Edelman: While primarily a PR agency, Edelman also offers digital marketing and has worked with many Fortune 500 companies on their digital campaigns.

7. R/GA: R/GA is known for its innovation and has worked with brands like Nike and Samsung on groundbreaking campaigns.

8. Droga5: Famous for its unique and often emotionally charged campaigns, Droga5 has worked with clients like Under Armour and The New York Times.

9. The Martin Agency: Known for its work with GEICO and other brands, The Martin Agency has a strong reputation for creative marketing.