This is one thing that you should do that does not help in your earning. Let me put it this way. It does not help but protect your earning. It’s an insurance that you need to have just in case something happens. You don’t want to lose everything after few years of hard work.
If you are hosting for your own blog using WordPress, then it should be no problem as there is a backup function. If you are using Blogspot or WordPress.com then you might need some other alternative ways to backup your blogs. You might think that having your blog in free hosting services like Blogspot might be safe because they are big company and under Google. But trust me guys, accident do happen no matter how big or how good you are. Better to be safe than sorry. I’m able to locate 2 sites that provide backup services as for now. I’m currently using one of them to back up my other blog on Blogspot. The services are free, so just use them.
P/S: Unfortunately the 2 sites are no longer available.