lots of boys create blogspot site on blogspot but not work which is not good and blog not get rank in google and so one day it lost all pages index convert into de-index. so every free blogs also need SEO if you improve keyword ranking then free blog also can give you earning like through googlee adsense or advertisement or link sale if your blog has good page rank.
so why you waste your time when you create blog then do on-page and off-page on your blog and find good result.
I thing worry what is on-page so read clealry:-
you can improve your ranking in google through on-page
features of on-page which will effect your page rank and alaexa rank in google and all other search engine.
1- keyword setting in website
2- less then 42 word in description - no long
3 - good title- post your definable title
4 - Use H1 in heading
5 - read more on-page
What is off-page
off-page is equally important as on-page important there are some features follow:-
1- directory submission
2- article submission
3 -blog posting and comment post
4 instant blogs and many more click here
Main question was how to improve ranking of blogspot so i am solving your problem and also saving your time you can use following instant blogspot and save your time. All blogs are instant we have use it on our website and incres ranking.
So all blogs are instant and you can get good result from above blogs i will update more if you will give me good comment.