A full-service agency can offer all services in marketing under one roof. This is the essence of a full service agency. They can manage your entire campaign from start-to-finish, and usually have a lot of resources.
This is sometimes better than using a web agency, where you rely on them to outsource SEO to one company, emarketing to another company, and so forth.
What services are included?
Full services marketing firms in London are covered, with the exception of sales training and telesales.
Creative services (web, design, SEO)
Writing services (PR copywriting, editing, etc.)
Advertising services (online, and offline)
Data services (emarketing)
Perhaps the greatest reason to use a full-service agency is their ability to support your campaign as it grows. Instead of using one agency to design your website, another agency can be used as needed for graphics. This is a great way to build your brand and will not require any learning curve.
It's always worthwhile to compare several agencies in order to get an idea of their industry experience and the costs. It is a good idea to arrange a visit once you have narrowed down your choices. You don't have to pay the highest price, but that doesn't necessarily mean you get the best results. It is worth meeting the agency to get a feel for their background and support services.