In fact, many companies hire employees or pay people to write online newsletters to recommend their stock. Officially this is not illegal, but federal securities laws require the newsletters to disclose who paid them, the amount, and the type of payment. Most fraudulent newsletters fail to provide this information. Instead, they lie about the income they received, their independence, their research, and their track records. They stand to profit handsomely if they convince investors to buy or sell particular stocks.
Newsletters also use the pump and dump technique discussed earlier.
With enough people on the list it is possible to create movement in the price of small stocks.