Is Adsense made enough money for you? Well, not for me. I only earn very little from Adsense because I'm lazy to update my adsense website. This blog has no adsense ads because it has been banned by Google. But I do make some money from Adbrite, in fact better than Adsense.
If you have a site particularly set-up for adsense, you should do all the tactics discussed in this blog. I wrote many articles on tips for adsense in this blog for you to make good money from it. The same tactics may not relevant for other contextual ads because adsense ads is unique. Therefore you need to create niche articles and become an expert in that topic so more people will visit your site to get information on that niche. Your site may get more clicks because the ads appeared are relevant to the topic you wrote.
It's not true that in order to make money from adsense, your site need a lot of traffic. If you can target the niche market, you already have your own audience, even small number of audience can help you make money. Here, you need to target niche market with high paying keywords. Find out more about high paying keywords for adsense here.