If you want to give Mark Zuckerberg your opinion on Facebook's new paid messaging service - or anything else - it could cost you $100.
The company started testing the service last month with a small number of users, charging them $1 to make sure that their message went into the recipient's inbox.
Otherwise, when a user messages someone outside their particular circle, the message goes into the little-known Other folder, where it generally vanishes without trace.
"Several commentators and researchers have noted that imposing a financial cost on the sender may be the most effective way to discourage unwanted messages and facilitate delivery of messages that are relevant and useful," the company explained.
In the case of Zuckerberg, though, getting through doesn't come quite as cheap. As Mashable first noticed, the company's tweaked the system so that messaging really high-profile users, including Zuckerberg, costs a cool $100.
"We are testing some extreme price points to see what works to filter spam," a spokesperson explained.
Assuming that the $100 fee brings the same benefits as the $1 one - no personal dinner invitation thrown in, or anything - it will at least make sure that the message gets through. If Zuckerberg replies, answering him won't cost any more; but if he bungs your message into his spam folder, you'll never get through again, however much you're prepared to pay. Probably best to be polite, then - however great the temptation.