I feel like lash extensions really took off in California about 4 years ago. When I was working at Nordstrom in California I would get lash extensions applied for free from one of the trainers of Novalash. I had some of the best lashes in the biz and one of the best trained people applying them. And man were they a hit! All of my clients were lining up to get there very own set of lash extensions. They looked so gorgeous! 

And they stayed gorgeous for about two weeks... then they started to fall out. Just like a normal lashes would, but sometimes they wouldn't fall out evenly and my lashes wouldn't look full and thick anymore... they would look patchy and sparse. A trip to the salon to have the lashes touched up would fix that. But they never look as good as the first time they were applied. The process of getting rid of them is really annoying too because you will have patchy, clumpy lashes for about a month while your lashes grow out and the extensions fall out. 

That being said, extensions are a great way to quickly get great looking lashes that will look beautiful for about 2 weeks. What I usually recommend to my clients is to start using Neulash or Revitalash about a month before the wedding. If you can get your natural lashes to look beautiful, that's the best way to go! And if that doesn't work... then go with the Extensions. I recommend getting extensions about 3-5 days before your event.