Plant seeds at every opportunity
Not every customer is going to buy from you today. We all know that. But give them the opportunity to do so.
Source: Peter Smith, sales speaker/author
Believe that they will buy now and behave accordingly. At worst, make sure the experience is engaging enough for the customer that if he/she doesn't buy today they will want to buy from you in the future.
Sales is a math game. The more effort you put into actually selling stuff, the more success you will enjoy.