One LLC for several services

In general there is no problem in selling multiple services or products from of a single company. Many many companies do that.

You might want to consider:

• Setting up your bookkeeping in such a way that you're able to calculate profit an loss for each business area individually. There is a fine line between good visibility into your business, and too much administrative overhead. Think about it, but having clarity on how each business is doing is vital.

• Branding / marketing strategy -- how do you brand and market each business area, and the company itself? Do you focus on branding the business areas individually, or the company, or a mix of both?

• Legal liabilities. The main downside to having just one company is that both businesses share the same legal structure. Should fx the eco friendly car wash be hit by a lawsuit or otherwise loose money, then the promotions website is also liable for the debt, i.e. the promotions website might go down with the carwash -- and vice versa.

And last but certainly not least: How about your own energy level? Do you have the resources to start two business areas at the same time, or do you risk starving each business of the attention it needs to succeed?