Back links improves the rank in search engine where as likes give you traffic...

If u have more likes that means, many members are following your website/page, so automatically u will get good traffic, by good traffic your site rank will be increase.

By backlinks also you can get gud traffic

Likes never increase the page rank, Page rank is increased only when we write good content on page.

Back link most important for your increase website

This is a wrong fact, that only with "likes" and without a single backlink you can improve your page rank.
It is very necessary to have proper bank links as well.

Backlinks are imp for increasing visibility where as likes for popularity

like hanya untuk menambah kepopuleran blog anda tetapi untuk meningkatkan pagerank suatu blog yang dinilai adalah dofollow backlinknya,itu menurut saya

Likes shows how many number likes your website but backlinks shows your website page rank

Back-links improves the rank in SERP

Backlinks helps to increase traffic on your sites.