Your word is everything. Nobody makes referrals to someone who is “kind of reliable.” Nobody makes introductions to someone who is “sometimes there.”
You’re either there or you’re not.
Especially in business (and you’d be surprised how small big cities can be … ), your word and reputation is arguably your greatest asset. If you say you’re going to do something, do it. If you promise to follow up, follow up. If you close a deal, make sure that deal is upheld to the highest standard.
If you are not able to do this, then all your other networking efforts amount to very little. For every lead in, two leads fall out.
Besides, a friend always keeps his or her word to a friend, right?