I'm hearing that some people have received Private Messages through Trip Advisor from businesses offering their services.
Everyone should know that under the TA guidelines, this specifically forbidden.
"No Soliciting - Private messages should not contain promotional material, special offers, or solicitation for services." from the Guidelines.
If you should receive such a message, please report this to Trip Advisor. One way to do this is to go to the Private Message area of your account, mark the message and click on "Report Spam."