Differentiating between a recruitment agency and a recruitment consultancy can be confusing; after all, they both work with businesses to find appropriate people with the right skill set for their roles. Whilst each serves its purpose, it is the process they adopt to reach the outcome which separates the two.
A recruitment agency will usually operate on a reactive basis and be volume-driven. After taking a job instruction they will send a number of CVs to a business in the hope that something sticks.
The recruitment consultancy will take a more proactive and qualitative approach. They will work with a business understanding the history, structure, challenges, needs, vision, etc so they can deliver a more service orientated approach.
Both the agency and the consultancy serve a purpose.
It is for you, the customer, to determine which suits you. The best advice I can give is to question the process so you can make an informed decision and avoid disappointment. In retail terms, I have bought items in Primark and Harvey Nichols. They both sell clothing and accessories. The products and the offerings differ drastically.

