I have had a look at your keywords, and I think there are some that people would not search for, such as NAPPS and those other acronymes. In stead, if they know about these bodies at all, people would probably search for the full name.
That lead me to making a google search for 'process server denver colorado'. Your company came third. Below are the key words of the company that came first:
<meta name="description" content="Checkmate, Inc. has been supporting Colorado's legal community for over 35 years. Our staff of Denver process servers are the most experienced in the field and equipped to handle all phases of service of process, court filings, DMV records retrieval and skip tracing / data base searches. Our staff of professional process servers cover all of Colorado and can facilitate service anywhere in the US."/>
<meta name="keywords" content="Process serving, Document retrieval, Asset Search, Skip Tracing, Legal Documents, Summons & Complaint, Record Subpoena, Deposition Subpoena, Landlord Tenant, Temporary Restraining Order, Bank Levy, Notice to pay or Quit, Wage Attachment, Cross-complaint, Evictions, Pleadings, Motions, Correspondence, Discovery, Writs, Small Claims Cases, Colorado, Denver, Front Range"/>
The second one didn't have any keywords, but I looked at the one on place 4:
<meta name="keywords" content="Process Service, Process Serving Company, Certified Process Servers, Private Process Serving Company,
Serve Legal Documents, Service of Process, Process Servers in Colorado, Serving Legal Documents, Serving a Subpoena, Serving a Summons,
Private Process Server, Serve Papers, Colorado Process Servers,Process Server Denver" />
<meta name="description" content="Elite Process Service, Denver based process serving
company for serving summons, subpoena and legal documents. Let our certified
process servers in Colorado and Nationwide provide prompt, reliable and
competent Service of Process." />
As you see, they are using the kind of services they are offering as keywords. You could try something similar for a while and see if that helps.