There are many examples of common scam messages in the cryptocurrency world. Here are some common types:

1. **Guaranteed Investment Letters**:

- These messages claim that there is a guaranteed investment opportunity with high returns. They often include promises of making large profits in a short period of time.

2. **Email Scams**:

- Messages that appear to be from well-known trading platforms asking you to update your account information or reset your password. They often contain links to fake websites.

3. **Free Offers**:

- Messages promising you free cryptocurrency if you send your coins to a certain address. These are often scams.

4. **Social Media Advertising**:

- Ads claiming that celebrities or influencers have invested in a particular project and urging you to join. These projects can be fraudulent.

5. **Direct messages from fake accounts**:

- Receiving messages from accounts claiming to represent well-known companies or projects, asking you to invest your money or provide personal information.

6. **Scamming via voice or video chats**:

- Some scammers use video or voice calls to increase their credibility, claiming to be investment experts.

7. **Fake Promotions**:

- Messages claiming to have a promotion for certain currencies, promising to distribute free coins or rewards if you invest.

It is always important to check information sources and not blindly trust unknown offers or messages.