Share your knowledge.
One of the benefits of an online journal is that knowledge shared can be accessed by anyone at anytime. So if you've come up with a creative solution to a common problem, have a wonderful recipe to share, or a fun way to help your child learn subtraction, post-it to your online journal. If you take the time to write it, chances are someone will appreciate it.
It doesn't matter if you don't know anyone who would be interested right now. 3 years from now, your cousin might want be curious about that traditional family recipe or tomorrow morning, a stranger from halfway around the globe may be looking for help teaching subraction.
In many respects, this is one of the most constructive and courteous entries an author can make.