Making $3,000.00 per month from your blog is very doable since that is $100.00 per day and you can easily do that by selling affiliate products or services.
Take for example if you make a sale of a web hosting account and get paid $100.00 per affiliate sale then you only need to make one affiliate sale per day to make $3,000.00 per month.
You can also make $3,000.00 per month or $100.00 per day with a blog and Adsense or media.net but to make $100.00 per day from Adsense or media.net and a blog you'll need around 3,000 daily unique visitors per day to your blog and a high paying Adsense niche such as Insurance, Web Hosting, Web design, domain names, health and fitness, weight loss, hair care etc.
You could also sell your own E book or products or services from your blog and earn $100.00 per day or more.
But do remember building up a blog to $100.00 per day or $3,000.00 per month will not happen overnight it will take time.
Expect to work hard on your blog for at least 5 years before you make any good amount of money.
It takes time to build up website traffic and SEO ranking takes time.