Wiltshire divides almost cleanly in half. Swindon in the north is a large, self-contained commercial town oriented toward the M4 and Bristol. Salisbury in the south serves a wide rural catchment and looks toward Hampshire and Dorset. Chippenham, Trowbridge, Devizes and Warminster sit between them, each serving its own area.
Very little commercial activity crosses between north and south. A business claiming to cover Wiltshire is usually claiming two markets it serves one of.
Swindon is not a small town
Swindon has a population larger than several English cities and an economy built on distribution, financial services and what remains of its manufacturing base. It is routinely under-estimated by businesses that treat it as part of a rural county, and its local search results are correspondingly less contested than its size warrants.
Salisbury serves a very wide catchment
Salisbury draws from a large, thinly populated area across south Wiltshire and into Hampshire and Dorset. Businesses there routinely travel considerable distances, which makes service-area structure more important than city-centre ranking. It also carries a significant visitor economy around the cathedral and Stonehenge, with the seasonality that implies.
The military presence is substantial
Salisbury Plain is the largest military training area in the UK, and the concentration of personnel and families around Tidworth, Bulford, Larkhill and Warminster creates genuine local demand with unusual characteristics — high population turnover, a steady flow of people new to the area searching for services from scratch, and demand tied to posting cycles rather than the ordinary calendar.
Businesses serving that market should say plainly that they work with forces families. Very few do, and the searches exist.
Rural coverage needs honesty
Much of Wiltshire is sparsely populated with long distances between settlements. Naming the market towns you genuinely reach — Devizes, Marlborough, Amesbury, Westbury — converts better than a county-wide claim you cannot service.