Every friendship starts with mere acquiantances. You get to know deeper and deeper by sharing both of your lives. You invest time and emotion for it to grow. Then, you share more with affection and trust. This is the level of true friendship for me. It's not just about the comfort level in the relationship but rather the love and trust that make it to the level of friendship.
Friends are our kindred spirits. Because of our love for our friends, we are willing to give our support or comfort when they need. But it's not the other way around (let me reiterate: it's not the other way around ;) ) We become a friend not because of the benefits that we can get but rather we share the love (support or comfort) because they're our friend. It's just similar to taking care of our little sister/brother.
Ergo, my only qualification is SINCERITY and not the STATUS SYMBOL. I have friends in different walks of life and I am growing with all of them. Part of me is left with them and vice versa... and I will always treasure beautiful friendships with them.