To get reviews directly from customers, enable 'get customer feedback' in the advanced settings menu.
This adds a link to the customers confirmation email which they receive when they make a booking. The link is then active once they have attended their booking.
When you receive a review, you'll receive an email and you can view these in the reports section of simpleERB. You can tick a box which sends an auto reply to the customer asking them to post their review on one of your social profiles (Trip Advisor, Facebook etc...)
You can set links to your social profiles up in advanced settings
Getting reviews directly can help filter out the negative reviews so you can deal with them privately. It also gives you a chance to tell your happy customers where to post their comments!