Sponsored Reviews – Lot of companies are looking for quality blogs for reviews as well as backlinks to boost their rankings. One can argue that its unethical to have your reviews sponsored. But in fact all the advertisement works that way. When you see advertisement on TV, the football star is paid to speak about the product. So its hardly unethical. If your blog is theme based and you maintain high quality original content, you can approach companies/websites that you can do review for them. You can earn upto $20 to $50 per review.
Advertising – Most of the bloggers use this method to make money. There are plenty of options to place automated advertising on your blog. All you have to do is put code provided by the advertising company and you will see ads being served on your blog. The income will depends on number of visitors that visits your blog. There are option for text ads, image ads and video ads. Some of the popular ad networks are Google Adsense, Chitika, Bidvertizer, Yahoo Network (only for USA bloggers) etc. You can also find advertisers on your own, this may help you get more money.
Affiliate Marketing – Bloggers and Webmaster have made tons of money using Affiliate marketing. Here you sell other people/company’s products and get commission on each sale. You need to have loyal followers to your blog. There is huge potential to make serious money if you have time to learn and adapt. The companies like Clickbank, Amazon, Ebay all have affiliates and they want you to sell their products.
Creating and Selling Your Own Products : If you are good at something and have information to share, you can create ebooks (digital products) and sell them directly through blog. You would ofcourse need some experience in online marketing.