I'm probably a bad example for what to do in terms of reviews, as I don't go crazy trying to get reviews. I get enough to keep them growing and showcase them... but my current approach is to let couples leave them on their own if they'd like. The reason for that is because I now primarily focus on multimedia content such as photos and videos. Also becuase I currently have such a strong word of mouth growth that works better than reviews (my clients are actively prmoting and recommending me to their friends and family).
Reviews are great and all, and if you're starting out I'd put a strong emphasis on them, which is what I did with video reviews and after each event I would send an email 2 weeks later thanking them for allwoing me to be a part of their night and if they'd like to write a review on google (I'd provide the link). However, once you have a nice collection of them, content is the key to everything.
Why....?
Well even mcdonalds can get great reviews. So can applebees and so can just about anything. But if you're looking to offer a premium product and attract premium clients, they want to envision you at their wedding. They want to see your setup and make sure it ties in, see videos and hear the type of music you play, how your add-ons look and function, and see how often you're active and what your consistently doing. Reviews just certify that whatever you do you do it well.
For example, say I have a 15 5 star reviews but you have 50... however your online content is kind of lacking... few and far posts made and generally nothing super high quality... just basic iphone content, etc. Whereas mine, the couple sees that i post regularly. They see my setups captured with professional cameras and looking flawless. More importantly they see countless videos of me and hear the music I often play. Say they're a high energy couple that wants a more trendy vibe or a club atmosphere. If they see my videos and hear me incorproating a bunch of remixes and edm tracks at a good number of my weddings, but can't seem to track that down on your site or social media, who do you think they're going to trust to execute it? Reviews only go so far on their own.