Commercial use means the customer can use whatever you provide to directly or indirectly (<-- like in your case with the logo) make money. When someone purchases your logo, I assume they look at commercial use as a given. In my field (music) it often is a separate extra and it makes a difference if someone uses my work for personal or commercial use.
Often, you can provide a commercial license. The benefit for the buyer is that he has an official document and he is able to proof that he owns the respective right to use your work commercially. Again, when it comes to music this can come in handy but I doubt there are many places that will ask anyone to provide proof of any commercial license when it comes to a logo.
Do you mean in form of royalties? It depends upon the license. Whatever you create from scratch will be yours (intellectual property) and you can set the rules. If you do not want your work to be used in specific ways, you can outline and prohibit anyone to use your work for example by prohibiting reselling, giving away or redistributing of your work as is.
From my experience, not everyone respects their limitations anyway. If they think they can get away with it, they will. Why would you sell a logo for only personal use?