Blog types

OK , back to business . Blog types , how many there are ? What are the most successfull ones ? Top 3 blogs' types :
1) Gadget/System Blogs
2) Fun
3) Commerce
Could a blog be as simple as SystemLog ? date , time , data . I guess so . Consider a Tag Count on a system output log. Its all the metadata used in one place marked by Date , Time , some more parameters , and all that is to leave a SysAdmin Confused (he has already seen a lot of that stuff). But , better yet , a scratch thoughts of a blog could be a Basis for Knowledge aggregation platform properly published all over the world and indexed by 5 most powerfull engines in the industry , i.e. your Blog could be a pen-to-paper scratch for a bigger Job. Part of a blog can appear as a comment or a citation on some other platforms , search results are being optimized for weeks , months and years .