Generally word of mouse is used in place of word of mouth when discussing online recommendations, warnings, and reviews. This site is an excellent example of that principle in action. You'll recall not long ago there was a thread(now closed) involving a gent with a poor trading record. That would be a negative word of mouse experience for that particular person.(The online warnings drive down his inability to trade)
On the flip side with the constant favorable conversations on particular blends of tobacco (Penzance, FVF, Blackhouse) on this sight these tobacco's gain a large following, and thus sell very well with little traditional advertising(IE: ads, samples)
Lifted from WiseGeek.org
Word of mouse is an electronic version of the time-tested idea of word of mouth. Numerous advertisers have jumped on this bandwagon, using a variety of innovative techniques to get their message out to consumers, and businesses all over the world rely on it to promote good reputations. As electronic media grew in importance in the late 1990s, word of mouse became a new holy grail of marketing, with a host of books, articles, and commentaries on how to get it.
The idea behind word of mouth is that people tend to rely heavily on the opinions of friends, peers, coworkers, and neighbors. Businesses have known for centuries that a bad reputation can be acquired very easily, and it is very difficult to get rid of. All a business needs is one person who complains about their service to a friend, and a bad reputation can snowball. Conversely, people who praise a business to friends can create a good word of mouth reputation.
Often times reviews and conversations such as these are fabricated(either by the company, or paid representatives they refer too if positive. Or possibly by competitors or a customer feeling slighted if negative). It is significantly easier to fabricate this type of advertisement than word of mouth based on the ease with which a user can remain anonymous online, even to creating multiple profile in order to create good reviews. A well built site can put controls in place to help prevent this, and often times will ban users deemed to have "violated the trust" (yes, that is a bit of bootlickery in the PM Forums general direction there)
Or say I came up with a perfect clone of Blackhouse, could sell it at my own website for half the price. I would most likely send a sample out to a few people I know like blackhouse, one of them writes a great review of it and happens to mention that when they came back to order a 50g tin of it, my customer service was amazing, it was less expensive than blackhouse, I sent them a personable e-mail, and threw in a pack of BJ long's pipe cleaners, or a book of matches, or a 1/2 oz of another blend I make, and had it delivered by swimsuit models. The word of mouse traffic from this site would most likely drive my demand until I could not match it with my level of production, and fairly quickly, unless I had anticipated it and had enough backstock to keep up, while I revamped my production.
All in all "word of mouse" is a way of expressing just how easy it is to have your reputation, and therefore your business made or broke by your customer service in this world where anyone can communicate with hundreds if not thousands of people about the undercooked chicken you just served then, or the thoughtful non gratis dessert you served them when you found it was their birthday, before they've even gotten up from the table.
It is no longer , as my Walmart training put it, If you do everything right and make a customer's day tell two people, if you don't they'll tell ten. In this world of high speed communication, where everyone is connected to all the people they know all the time, you have to add a few zeros in there, on both sides.
, I've never heard that term used like that before, so you're not alone.