Yes, we all know the elevator speech should be brief, that it should be how you help someone or a company solve a problem but it is also important that the person understands what you do.
So try this... explain to a high school student or your favourite aunt what service you provide. THEN, ask them to explain back to you what you do. Be open to clarifying questions.
Once you can explain your service in a way that doesn't require specialised knowledge, you will have the basis for a great 2 minute introduction to your services.