Do they actually work?
No, they don't actually work. These are set up as a trick to get you to give out your information so that someone can take your account and/or all of your Robux and items. There are a lot of great ways to purchase or earn Robux on Roblox. Building amazing games or creating awesome clothes are just a few ways to do so. A list of how to buy or obtain Robux can be found here. Builders Club can be purchased here with parent permission and guidance.
What should I do if I see these?
Report messages or links like these right away by clicking on the Report Abuse links/buttons located around the site and in every game menu. By doing this, our moderators will be able to take the appropriate action against those attempting to phish or scam your account information and you will be helping to make Roblox an even better place! More information on how to use our Report Abuse system can be found here.
You can also adjust your Account Settings to prevent these messages by clicking the Privacy Tab and selecting who is allowed to send you messages, chats, and more. To reach these settings, click the gear-icon located in the upper-right corner of the site and select Settings from the drop down menu. Alternatively, you can click here.