I'm a beginner, Google and what else?

[salvo]

Hello there,
I am new in the world of web marketing so I'd like to have some advice from you to know what are the better ways to "make the things work better". We want to sell a product and we have created a Google campaign which is working fine. We set up adverts using Adwords and Adsense and we constantly check stats by using Analytics. Do you think Google is actually the best service for web marketing? What about yahoo, msn, ask.com, 7search? Which one do you think is the best one? I'm having a look around the forum to see past threads and I've seen a few things that could maybe help me (I'm sure i'll find more if i'll keep on searching). What advice can you guys give me?
Thanks.