Please note that if you post any personal details such as email addresses or phone numbers in your message you will likely receive offers from taxi drivers monitoring the site. If you do not want this then the best option is to register and use the private message function.
If there is a delay in your comment being posted to the site it is most likely waiting to be moderated. The spam filters are set high to detect unsolicited advertising.
It is always recommended to confirm the identity of any person you contact on this site through another means other than email, e.g. Facebook or a phone call.
If a taxi driver contacts you claiming to already have people wanting to share, be aware that it may not be true. There is a chance he will then arrive empty (as planned) and you will have to pay the full fare.