Disclosure policy

My Google statistics shows me that disclosure policy is third most popular link on my
website. Why In have disclosure policy? Because I love blogging and I would also like to make some money with my blog. Last month I joined two companies, which pay you for writing reviews about products and services. Sometimes I will write some sponsored article and earn a 5, 10, maybe even 30 USD. Articles will be of course connected with my site style and I will not reviewing things which I don't like. This articles will be marked with label: sponsored post. I think this is good way of earning money online. What do you think? Do you have experience with earning money with writing reviews?