Hair is one of the most visual local services there is. Someone looking for a new colourist scrolls Instagram, checks the Google reviews, opens the salon's website and decides in under a minute whether it looks like their kind of place. If the photos are dated, the price list is hidden or the only way to book is a phone call during opening hours, they move on to the next result.
Salons also have a retention problem hiding behind an acquisition problem. A new client who books a cut and never returns costs the same to win as one who returns every six weeks for years. Good salon marketing is therefore less about shouting louder and more about attracting the right clients, such as colour and treatment clients, and making the second booking easy.
The other challenge is capacity. A stylist's day can only be sold once, so advertising needs to be aimed at the services and time slots you actually want to fill, not at whatever generates the most clicks.