What drives internet retail promotion is convenience of immediate gratification whereas store-based promotion is shopping experience of buying from a physical store location.
So, the carwash website should communicate attributes and benefits in terms of quality, service, prices, product information, etc., that makes shopping experience more pleasant than the competition.
Start with goals and objectives.
Why do people visit carwash and return? Answers are clean, shine and protect their vehicles and customer satisfaction.
Here, website should clearly distinguish two niches served – DIY (wands) and DIFM (in-bay).
Then what are attributes and benefits of DIY and DIFM?
For example, if you sell rain-x total body, website should explain the value added in terms what the product does (protects glass, paint, rims), how long it lasts, price, etc.
Generating revenue directly by selling unlimited online (price discounting) is only great if wash has built-in capacity to service the demand.
Otherwise, generating revenue indirectly by offering a
loyalty program (VIP card) and e-mail promotion (or phone
app) to get customers to visit the store would make more sense for self-serve.
Plastering carwash website address everywhere conceivable can be uses as a form of site optimization.
Although Facebook is primarily for making friends and socializing, it does present an opportunity for folks to link-up and visit the website and ultimately the store.
Judging success is difficult because carwash is not click’s business.
For example, as far as I know, there is no way to relate change in “likes” and “dislikes” with change in car counts or wash revenues.
Consequently, I recommend operators rely on customer satisfaction surveys conducted on premises as a method to measure change.