i don't know who is the "we" that knows it's fake. Statistics shows quite the opposite:
90% of online consumers trust recommendations from people they know;
70% trust unknown users, 27% trust experts, 14% trust advertising, 8%
trust celebrities (Econsultancy, July 2009, Erik Qualman,
This is just an example of course. There are hundreds, probably thousands of similar studies, but the proper path is to do your own testing.
See, you're asking about testimonials, as if they were the same thing across sites, or using the same techniques, or working in the same context. In fact, there are (literally) hundreds of different combinations, going from generic testimonials with generic stock photos, testimonials from people on social media, testimonials with mail addresses to contact the person who gave the testimonial, testimonials with video, really short testimonials, testimonials that are a page in itself.... well, just some different ways to show a testimonial.
Wanna talk context? OK, think about any of the combinations above and now think about the difference depending on where are you seeing the testimonial. For example, would you expect the same level of trust on a testimonial in a page by Apple than in a page for an online casino? I doubt you would!
Wanna talk trust? Do you think it's the same a testimonial by John Doe with a stock photo than a testimonial by a real life like user? An individual that a representative of a company? Someone with a contact than someone that doesn't display any way to contact? And we could go with this for days
As you may see, there are countless ways of working with testimonials, but bottom line is people trusts them. For a law of averages, for the psychological will to trust, for simple reinforcement (and there are LOTS of studies about these aspects too), there's a noticeable difference between a site with testimonials and one that doesn't. Otherwise, you'd be saying that thousands of reputable and successful companies are doing this in a lame attempt to fool clients. AND they didn't even test what they do. As you may imagine, this is far from truth
Companies will obviously display the best testimonials they can find, but it doesn't mean they don't have real people willing to vouch for them. And let's not even start with paid testimonials!!!!
Bottom line, if you think all testimonials are fake... well, rethink it. And yes, they work.
Different ways to display testimonials