There are many digital marketing agency London, each offering a range of services to help businesses with their online marketing needs. Since my knowledge is current only up to September 2021, I don't have access to the latest information about specific agencies or their current status. However, I can provide you with a list of well-known digital marketing agencies in London that were reputable as of my last update. Please keep in mind that you should conduct your own research to find the most suitable agency for your specific needs. Here are a few agencies to consider:

1. Wolfgang Digital: Known for their data-driven approach to digital marketing.

2. Croud: A global digital marketing agency with a presence in London, offering a wide range of services.

3. Relevance: Specializes in luxury digital marketing, particularly for high-end brands.

4. Verve Search: A well-regarded agency known for its expertise in SEO and content marketing.

5. Brainlabs: Offers a range of digital marketing services and is known for its innovative approach.

6. R/GA London: A global agency with a strong presence in London, offering a wide range of digital marketing services.

7. Merkle: Known for data-driven and technology-based marketing solutions.

8. iCrossing: Offers digital marketing services with a focus on data and analytics.

9. Jellyfish: A full-service digital marketing agency with a global presence, including offices in London.

10. The B2B Marketing Lab: Specializes in digital marketing solutions for B2B businesses.

11. Biddable Media: Known for its expertise in paid advertising and PPC management.

12. Greenlight Digital: Offers a range of digital marketing services, including SEO, PPC, and content marketing.