
The first thing you should work out is what you want in your website and how you are going to measure success. Then ask them if they are eligible to approach your needs or not.
If your company delivers the website or services that brings return on investment, ask your company if they can provide exact and tangible results.
Ask the company for client feedbacks, testimonials and performance data for their work and how they delivered the results.
Your company should understand your sales process because that brings traffic to your website. Don't forgot to ask them for what tools or service they provide to measure traffic of your website.