The way most brokerages makes money is by handling your trading, and they want to you to make many trades. Brokerages wants you to trade a lot.

Online brokerages today have a fairly low commission, some charge based on the number of stocks purchased, some have percentage of the total value of the transaction and others have a flat fee per trade.

It is not investing to flip in and out of stocks on a day to day basis. What is smart for the long term investor goes against what the brokerage wants. They may not say it out bluntly, but for example emphasizing how convenient it is to buy and sell.

From Ameritrade:
“Did you know you have eight ways to place trades online with Ameritrade? You can place your order from: Streamer Suite™ console, SnaptTicket™, Balance and Positions page, QuoteScope™, Advanced Analyzer™, the Trade menu, the command center screen, and Trade Triggers™. Explore all the ways Ameritrade makes it simple and convenient to place trades”.

This is not something that is special for Ameritrade, but it goes for all brokers, online or not. They live for the commission. It is nothing wrong with that, but something to keep in mind.