If you are selling products, definantly. If you mean more like, a "bussiness," then yes, build trust and great customer support before anything else. Once you finally have customers, then think of monetizing your site.
If you are making something, such as a gaming or video site though, then there is a different story
You don't really have trust in the customers or need much support.
Now, if anyone understood what I said, please tell me, because I had a hard time understanding what I was thinking.