The most Twitter-savvy brands itself use Audiense to understand what micro and macro accounts (brands, people, publishers) influence their markets or industry.
With this information they are able to:
Advise what the best brand strategy is to reach certain audiences
Advertise to engagers of those accounts.
A leading worldwide agency used Audiense in order to compare the trending accounts identified to a client with custom benchmarks (e.g.: cities, countries, competitors...).