@ Asker 17:01 Jun 25, 2017
Your parsing seems to be confusing you — the elements do not belong together as you seem to suggest. You need to look at the overall structure:
"It [a real etsate company] may also find information on social media ... helpful to make the sale" — I don't personally find anything wrong with 'helpful to make the sale', though 'helpful in making the sale' could also work.
After that, all the things listed in between '... such as a person’s aesthetic preferences, family situation, and how often he or she entertains friends...' are simply details, to be treated separately. | 
