In my opinion, microblogging won't generate a lot of income as compared to blogging.
Blogging had a lot more flexible options like advertising, sponsoring, etc which aren't available at many MB services.
Moreover, you can't make a long description for any affiliate product.
The only plus point I've noticed is that you can disguise links and people who generally tend not to click on affiliate or referral links, will have to click them. On blogs it becomes obvious to a person that any masked link would most probably be a referral link.....and unfortunately, most people in this world don't like other people to benefit.