True, but a stranger can't exactly be recommending services to you, for this to happen the person recommending the service to you has to be someone you trust, and the person must have had first hand experience with the company in question or knows someone who has and of course forums like this one help to as you even get access to a wider array of potentially satisfied customers who may have required their services in the past and can recommend them to others, this way the can reach a wider audience and market their services to so many other people who might be in need of it
Apart from being someone you trust, the person ought to have make use of the service too, I don't think it is enough for someone to just recommend something to you just like that, I think such person will have to make use of the service atleast with that he or she can actually come up with a good reason why he should be recommending such service, recommending a device when you have not actually make use of it is risky that's why it doesn't even have to come from a total stranger, that's my take on this.