Ask why the Chinese town of Liushi, in Yueqing, can supply circuit breakers, switches and relays at the scale it does, and the usual answers are cheap labour and efficient processes, both true and both incomplete. Low-voltage electrical manufacturing started growing there in the late 1970s, and today component makers, stamping and moulding shops, copper and plastics suppliers, testing services and logistics firms all sit within a short drive of each other, so an order of almost any size can be split across many producers and a failed supplier replaced within days. The concentration is itself the competitive advantage, and it carries a consequence industrial marketers rarely act on: when an industry sits in one place, so, likely, does the market for everyone who sells to it.

For a company selling into an industrial sector, the market typically has an address. Knowing that address, and the reasons the sector settled there, opens a set of channels that reach buyers where they physically work and largely ignore everyone else, from geofenced search to outdoor advertising on the roads into or within a zone.

Why industries cluster

Alfred Marshall described the mechanism more than a century ago, and it has held up well. Firms in the same industry gather where they can share a pool of skilled labour, draw on the same specialised suppliers and pick up know-how from each other through hiring and imitation, so that each new arrival makes the location more attractive to the next. Physical factors decide where a cluster starts, whether that is a port, cheap land, reliable power, a raw material or a favourable regulatory regime. The Ruhr grew on coal and steel, Rotterdam's port anchors one of Europe's largest petrochemical complexes, Houston's energy industry followed the oil, and Jebel Ali's free zone and port drew logistics and trading companies to Dubai.

China as the extreme case

China industrialised by building this effect deliberately and at scale, to the point where single towns and districts specialise in one product: socks in Datang, eyeglasses in Danyang, small commodities traded through Yiwu, electronic components around Shenzhen. A buyer sourcing a part there chooses among dozens of producers within an hour's drive, each able to absorb a share of a large order, and that depth explains much of the price advantage usually credited to labour cost alone. The same logic operates at smaller scale almost everywhere, from the automotive suppliers around Stuttgart to the energy services firms along Houston's energy corridor.

What the map means for a marketer

A sector that clusters puts its buyers, their suppliers and their competitors within a few kilometres of each other. Most digital campaigns ignore this, because they are set up by country and job title as though buyers were spread evenly across the territory, and the budget follows that assumption. The demographics around a cluster matter as well, since workforce housing, the commuting corridors that feed a zone and the districts where managers live all shape where a buyer can be reached outside the office.

One complication needs planning from the start. The site and the decision are often in different places, so a French carmaker's assembly plant in Morocco runs the production line while engineers in France approve the components and central purchasing signs the contracts. A useful map marks both where the product is used and where the purchase is approved, because the two locations frequently call for different channels.

How to research your map

The research rarely needs a commissioned study. The fastest start is your own CRM, since plotting the addresses of your best existing customers often shows a concentration before any external source does.

Industrial city and free zone authorities publish tenant or member directories, and municipal land-use plans show where industrial activity is permitted and therefore where it sits. In developed markets, chambers of commerce, industry associations and regional cluster organisations often hold member lists and sector studies, and several European regions fund cluster bodies whose job is to document exactly this. Google Maps listings can then be scraped by business category inside a defined area to count the companies that match your buyer profile, and keyword data for that area shows whether enough searches exist to support a campaign.

The result does not need to be precise to be useful. A list of five zones ranked by how many target companies each holds, with a note on who buys and where the purchase is approved, is usually enough to change how a budget is allocated.

What to do with the map

Geofenced search is the most direct application, and we have written separately about how to set it up and where Google's idea of location misleads. Display and programmatic campaigns can carry the same boundaries, and programmatic platforms can target devices seen inside a drawn area, which reaches buyers before they search for anything.

Outdoor advertising, which most industrial marketers dismiss as a consumer channel, becomes efficient when the boards sit on the roads leading to or running within a zone holding a large share of the target market, because a high proportion of the people passing them work in the sector. Zone-level events, sponsorships and the business councils that operate inside free zones put a supplier in front of tenants in settings where a conversation is expected. Field sales routes and direct mail can be planned around the same map, and trade exhibitions are worth treating as temporary clusters, where the geography of a market compresses into one hall for a few days.

Some markets do not cluster, and the method should be dropped where it does not fit. Utilities, retail chains and agricultural operations are spread across a territory, and for them a map shows coverage instead of concentration, which calls for a different plan altogether.

The map has to be redrawn whenever a company enters a new country, where the zones, the clusters and the reasons behind them must be learnt again. Most industrial companies can say exactly where their own factories are, while far fewer can say with the same precision where their customers operate, and the second answer is usually the one their marketing budget depends on.