In our old home back in 2007 to 2008, we had requested the service of Nutri Lawn to perform a complete, thorough weed removal both in the front and back of the house, especially at the back of the house as there was quiet the weed infestation.
They came once in two weeks or once in a month and would spray the back and front to remove the current weeds and prevent future ones from growing.
Initially it did the job but after a month's service, they did not do a great job as there were weeds after weeds growing at the back, side and front of the house. We had called to complain, and once again when they came, still the same problem.
They even over billed us for the job, and we had to call and complain that they had not done a good job in the first place. Eventually we gave up and had to contact another company for weed removal.
Perhaps despite the great rating, we might have gotten unlucky.