As I have my niche, reason number two is justified. When someone searches from Google about making an image bigger in blogs, usually, they end up with this
post here and other online and web-related stuff are in this blog. This means that when a searcher lands on the blog, there a good chance that he/she roams around within the blog and this is a good thing for the blog owner.
If you may have noticed, I have so many Google adsense scattered around. I try to earn from it although I am currently on aorounf $50 level of earning and maybe two more months aways or can be even 4 months away from my first check but that is not a problem. I am just happy running those ads here as I thing the blog looks more legit with a Google Adsense ads on it. The more blogs I have, the more places/spaces/spots to place my ads on and that would mean more impressions. So far, I have improved my average daily earnings 3 folds when I decided to get my blogs updated and nurtured (still not a big earning though).
Reason number four is more on traffic and Search Engine Optimization (SEO). The more concentrated the key words are, I believe the posts get searched easier. This is more related to reason number two as well. Niche thingy again.
More ways to eran as more ads can be placed. More ways to learn as well as I have to research on some topics I want to share at times. I hate to post crap here and I try to refrain from posting nonsense as much as possible but still, I am sure you see a lot of nonsense in many of my posts around. :) But all the same, well researched, well presented post gets traffic and gets on top of Google or other search engine searches.
Isn't it obvious then that the more blogs there is, the more ways to express? That one I love!
It's not all heaven though. Having many blogs means commitment. To make them all active and succeed need some time. I mean, you need not really post ten articles each but for me, I try to at least post 2 items in each of them in a month. That is not so much but I try hard to make the posts indexed good and be searchable. Building traffic is also another thing that can eat ones/blogger's time.
One thing though: Don't get addicted. I do blog as I find it as my relaxing hour after office hours but I think if you have kids and you are very busy, don't worry, just leave it behind. The blog is there to make you relax, not to pressure you up. Keep blogging if it's good, if it's not, forget about it!