Want to influence people? Then find groups and communicators who talk about whatever it is you want to influence people about and then connect with them. Influence people that influence other people and you will be able to influence lots of people.
There is a saying for new kids at a new school, want to be popular, then make friends with the popular kids. It is the same in grown up life as it is in school. The cool kids play with the cool kids and the rich kids play with the rich kids.
So you want to influence people how do you do it in the digital age? Use a social media monitoring tool like Brandwatch and listen to who is talking about you and who is influencing people in the community, who are the cool kids and who plays together and who people listen to. See it you know anyone in the group or if you know anyone of your friends who knows someone in that group. Get an introduction if you can. What events do they go to, go to the events and see if you can meet them in real life. If not get to know them online. Comment on their blog, get into conversation on twitter or Facebook about something THEY like to talk about. Then when you have developed some contact see if you can help them. Then ask them about helping you. Once you are in the group ask if you can be referred around.
Have I missed anything?