How many times have we looked up a product or service (especially apartments and auto insurance) only to see a bunch of negative reviews. All of the apartment complexes I've lived in since I was in college have gotten trashed on those review sites, but I've had great experiences in all of them. Well, minus the apartment where I stayed during my internship with the roach infestation (in the kitchen!!!!) that I finally conquered with roach bait stations.
I would say that in most instances, companies only hear from customers when things go wrong. Well, what if we could change that and highlight those employees who made our consumer experiences so positive? When it comes to layoffs, your positive letter/review could play a role in that employee keeping his job. That praise could also contribute to the employee possibly earning a raise and/or promotion!
Yeah, I know some people are thinking "my one letter is not going to do anything significant." If someone sent your boss a positive letter praising your performance, how would you feel? How many times do we forgo doing things because we think our "little" contribution won't have any impact? Doing something is better than doing nothing.