Another reason to blog for dollars is what I call the library affect. Many people visit their local library. Few ever consider the library makes money when you return materials late. You can rent space at the library. Your public library offers many services yet there are not all free.
You might ask how this applies to blogging? You can make money with your blog today. With little to no expertise, all you need is the willingness to write and post.
Consider your blog a resource. Even if you manage it part time, your library (blog) can earn you large dividends. The more you write the more you have to offer. The more resources available to a visitor when the search engines find you. This increases the potential ad revenue. It also adds to the ability to offer special products around niche marketing. Just as a library has many services, your library (blog) can offer many things or a particular one. The decision is yours.