Strange behaviour of G+

I was checking my feed in G+ as usual, Posts, shares and +1 of people and pages of friends, whom/which I followed.  Then I saw a post of php in my home feed from a person who is not my friend and to whom I am not following.

Was it an add or promoted post as in facebook. Facebook has lot of spam like these, that is why I rarely visit it. But friends are friends and most of them are in facebook, which is why I sneak to facebook without making any buzz.

Then why Gooogle put the post in my home feed in first place?

Recently I and my Elite team are working on project “Community cafe”. We were working on php training to urban rural areas of Kathmandu valley. We were bombarding the google search engine with php related search. We googled php for almost a week and google must have identified me which is why the post is in my feed in first place.

I googled other key words too such as wordpress, joomla, sketchup, autocad etc….. but none of them in my feed.

So question is,

1. Is google suggesting the post to me?
2. Is it hit and the miss of chances only?
3. Is google is starting to promote post and pages?