Bought demand in the DMV splits three ways before you write a single ad
Account structure should mirror your licensing and dispatch reality, because the auction does not care that the metro feels like one city.
Start with a plain question: which jurisdictions can you legally and practically work tomorrow. The District, Montgomery County, Prince George's, Arlington, Alexandria, Fairfax County. Anything you cannot serve does not get a campaign, a keyword or a dollar.
Once that list is honest, campaigns follow it. One structure that works is a campaign per jurisdiction group, each with its own budget, its own landing page and its own phone number. Costs and close rates differ enough across the river that blending them hides the truth.
Separate budgets also let you throttle independently. A crew tied up in Silver Spring for three weeks is a reason to pull Maryland spend and push Northern Virginia, and that is a two minute change in a structured account and an impossible one in a single blended campaign.
Resist the temptation to let automated bidding smooth across everything. Automation optimizes toward whatever you feed it, and if the conversion signal is form fills from a county you do not serve, it will cheerfully buy you more.