By definition, you are.
If it's useful or not to be called an author as in "has created a meaningful piece of writing" (apart from listing your groceries) is a completely different question.
Let's say... you have someone who has a personal blog, and he writes about e-readers. He posts 4 articles a day, testing and reviewing e-readers and applications. He does it because he finds it a fun way to spend his free time beside a day job.
Is that person an author now? Using your point of view, that person is not.
Now, that site is bought by a large company, and that same person keeps posting 4 articles a day, testing different e-readers and applications. The only difference is that he is now paid $500 for his trouble. He still needs to keep his day job.
Is that person an author now? In your point of view, he would be, because he earns $6.000 a year now, posting those articles, despite doing nothing different or extra; so, solely earning money makes him an author, or not.
That's not logical. There are quite some (classic) authors/painters/musicians/artists that didn't make a dime on anything they created.