Where do we go now?

Last night, I talked on the phone with my best friend. She is a female. We've made our nightly chats a ritual and its something I look forward to everyday. We live far away from each other but we care about each other too much to lose contact with each other. We really like each other and I could see us dating if I lived closer. Anyway, so last night, after we said our goodbyes and hung up, I sent her a text saying 'I love you,[insert here name here].' I knew I wouldn't get a response, I didn't, and it makes me wonder why those three words are such taboo. We haven't had a romantic relationship yet, but why does that dictate if I care about her or not. In all fairness, I do believe the sanctity of those words should be kept by not over using them; but I want her to know she means a great deal to me, that she makes me smile and laugh like no one else does, that I appreciate everything she does, everything she is and isn't.