An LSA agency can often identify and fix obvious account issues within the first few weeks, but meaningful performance improvements usually takes around 30 to 90 days. The timeline depends on your market, service category, competition, budget, and the condition of the account when the agency takes over.
Meanwhile, you may see early changes in lead volume, lead quality, or cost per lead within the first month. However, it takes a little longer to determine whether those improvements are consistent and actually lead to more booked jobs and revenue. If you have hired a good agency, they should set clear benchmarks, track results regularly, and explain what it is changing and why.