The term Industry leader is thrown around far too often in the staffing industry without merit. If everyone is number one then who is #14? Are all agencies tied? Of course not. So next time someone says that they work for the best or one of the best ask for proof.

How many billable consultants do they currently have in the area?

What is the tenure of the account manager or recruiter that you are working with? Don't fall for terms like average, combined etc.. Be specific to that individual. Ask to see their Linkedin profile.

How many clients are currently working with the agency? Again be specific. Everyone throws around Fortune 500 but how many are actually doing meaningful business with those companies?

What type of turnover has that office been through? Will you be working with the same account manager and recruiter today that you were working with yesterday?

Compare benefit costs. Larger companies typically have better rates on benefits and offer a wider variety. If you are paying a high rate then the chances of you working for an industry leader or slim.

Hiring managers, ask for metrics. How many C# developers have they placed that month or quarter. Again, you can't go off of old data so be current.

If you take the time and qualify who you are doing business with then you will truly be able to work with industry leaders.