It is very good to always let people know what you do, as sometimes the best deals come from that. Always network, and it would be good to join your local Real Estate Investing Club.
But in regards to marketing, it is better to go deep and not wide, so select a target market and hit it. For instance you can pick a few specific cities and stick to them and try doing as many deals there. Or you can target a specific type of seller (pre-foreclosure, probate, divorce, etc) and market to one of those only and stick to that until you get good at it before opening up a new line of leads. But the main point of marketing is to never stop, however you will market, continue it because it usually takes 6 months to really look back and analyze it from a statistical point of view to see if it was effective or not.
So my suggestion is:
1. Pick a target market
2. Decide how you will market (bandit signs, direct mail, etc)
3. Stick to and and keep marketing for at least 6 months