Hi Ana,
 
I also vote for the null option :-)
 
Google Trends can help if you need to check on how often a particular phrase is used.
  
Mouse over the red lines for the actual numbers.
 
It �s an interesting question, definitely not a silly one, because it shows how we associate new things with things we already know and apply the relevant  �old � prepositions.
 
"Search in this blog" because a blog is a text and similar to a book or journal, is contained and limited maybe?
 
"Search on this blog" because a blog is a website? Or is on a computer? (This one would be my least favourite, but I could imagine saying it)
 
"Search this blog" because a blog is three dimensional? Like a house? Too large to be  �contained �?
 
Does anyone think that these two sentences carry the same meaning and strength:
 
  "Search in this blog for the writer �s recipe for pumpkin soup"
and
  "Search this blog for the writer �s recipe for pumpkin soup"
 
 They feel slightly different to me.
 
Tap