Perhaps this site has been around awhile and I'm only hearing about it this week. Basically, if you need some yardwork done for your home, you go to the site and input what work you'd like done. Lawn Companies will go into the site and provide bids for the work. The homeowner can then choose a company and pay the lowest cost available.
When you receive the bid, you'll receive information about the company so you can check them out a bit (which you should obviously do).
If you are a Lawn Company or know of a good Lawn Company, there is an option to sign-up so that you may provide bids to homeowners. I'm not positive of the cost for this option, but its a great way to pick up additional clients.