Other people's lives
I spent an hour the other day looking at other blogs at random and quite scary it was. Apart from the people who write illiterate, obscene or just plain boring ones, there seem to be many who use their blog as a sort of vomitorium, and pour out long-accumulated bile, either against the world in general or—as in the case of one woman whose blog I encountered—against her whole immediate family: mother, father, brother, husband, sister-in-law and mother-in-law, all of whom appear to be utterly hateful. I expect it made her feel better, though if none of them read it there doesn't seem much point, and if any of them did it can't have done the family relationships much good.
Still, it made quite a good read, much better than those dreadful self-congratulating blogs which tell you how gorgeous is the spouse, how successful are the children and how absolutely marvellous is the life they lead in their lovely home, with photos! Much-adored happy families are so much less interesting to read about—and less believable—than loathed and miserable ones.