What does "standard message and data rates may apply" mean?

[TB13]

I joined Twitter mobile and it said that Twitter does not charge, but standard message and data rates may apply. What does that mean? Does it cost?? HELP!!!

[proudsong946]

It means that if you dont have a text message or data plan on your phone, your cell company will charge you for any messages you send or data to load twitter on your phone

[Andrew S]

It means that unless it comes out of some form of bundle you will have to pay your mobile phone provider for accessing Twitter from your mobile just as you will have to pay them for visiting any other website. There is no additional premium for Twitter specifically, it is just you have to pay for your basic internet access anyway.

[Aaron S]

That means your provider may charge if you go over the allowed amount of messages/internet. If you have unlimited texts/internet, you won't need to worry.

[Derek]

all it means is that if you don't have unlimited texting with your wireless carrie, your wireless carrier will charge you for a text message.

for example if you were to text your friend and you don't have text messaging on your wireless plan, it would cost you like 10 cents to send it,

so
all twitter is telling you that its going to be sending you text messages and if you don't have a texting plan on your account your carrier will charge you for texts. If you are allowed to text with your account then your fine.