I have been in the business for 8 yrs. I started out when I was 14 and now 23. I didnt get workers comp. on me and my 4 employees until last yr. Liability insurance until 2 yrs ago. It is a good selling approach. I have gotten several accounts due to this. However its not with it for residential unless you have a contract or a agreement wrote up. I got mine when a few businesses I put bids in told me I had the job but had to have liability. Depends on the company or person you are mowing from. They might want just liability insurance or they might want workers comp. also. Liability covers rocks or objects shot into doors, windows or damage property also other things it covers. I have used it bout 2 times every year that I have had the liability and pretty much paid for its self. I have found that "The Hartford" is a good company for liability insurance. They will send a check to the person that has the damaged property for the company the person recomends to use to fix there property. Also I like Key Risk for workers comp. key risk will send out cds, movies, papers and etc to help better your company and employees which has been very helpful for my company.
Hope this works!