i'm just curious to why you would spend so much money on advertising when you already have 125 customers? your business would already be well known in the area. seems you could go on word of mouth alone at that point which is free.
anyways i bought some signs 3 years ago. you can't put them inside the city limits or they take them down. you can put them in customer's yards but i think that's tacky and it's another obstacle you have to mow around. i just put them at intersections outside of the city limits. the city here isn't that big. i don't think i've gotten but maybe 1 call off of them and they are still up after 3 years. waste of money if you ask me. i also tried fliers and that was a waste of time and money as well. i put out like 1000 and got 1 call from them. the only thing that seems to work is word of mouth and i put an ad in the newspaper at the beginning of each season. i get about 5-10 calls from it each year which is better than nothing. every area is different but that is what works for me.
i also use free web advertising like yellow pages, thumbtack, angie's list, and facebook but i haven't gotten much from those things even though when you search lawncare in my area my company comes up on the first page.