As my colleague Rick Aristotle Munarriz recently reported, two major brokerages will soon become one when Ameritrade (NASDAQ:AMTD) swallows Toronto Dominion's (NYSE:TD) TD Waterhouse subsidiary in an all-stock deal worth about $3 billion.

With the two brokerages together sporting nearly 6 million accounts, the new company will be a major player. Total accounts will lag Fidelity Investments' 10.1 million and Charles Schwab's (NYSE:SCH) 7.3 million, while trouncing E*Trade's (NYSE:ET) 3 million. There's a decent chance that you are a customer of Ameritrade or TD Waterhouse. Many of our Fool Community members hold accounts at these brokerages, and some wondered what to make of the merger. Here are some snippets of conversations from our boards:

Joelxwil said: "I am very surprised that they are [planning to keep TD Waterhouse's] branches open. They provide dubious value, and I seldom met anybody at the local branch who knew anything of any importance."

Interestingly, in the financial media, some are hailing the acquisition by Ameritrade as smart because of the branch network it will get. Though many of us longtime Internet users may see little need for a brick-and-mortar post, it's valuable to other investors. As IndecisiveFool noted, the new brokerage may also benefit if it's able to offer new services through the branches, such as personal financial advice.

LuckyDog2002 noted with some amusement that his efforts to consolidate his accounts at various brokerages will be aided by the merger. "Now if Ameritrade buys Scottrade, I'll only have 4 other accounts to deal with."

Meanwhile, Allegra said, "I'm concerned about this merger. I've been a Waterhouse customer for 14 years and am very happy with them.... Are there any fans of Ameritrade out there to reassure me?" Reassurance was offered -- and more could be found on our Liquid Lounge discussion board, where savvy investors were mulling over the merger.

As Rick mentioned in his article, one key result of the merger will be reduced competition in the industry. This competition has kept commission costs low in recent years, which helps investors but can hurt those who are invested in brokerage companies, as price wars put pressure on profit margins.

How are you doing in regard to trading commissions? Are you paying more than you need to? Did you know that some brokerages are charging as little as $5 or $7 per trade? (Not that the commission price is all you should consider.) Learn more about some good brokerages and how to choose one that's best for you in our Broker Center, which also offers a handy comparison chart.

And finally, learn more at our Discount Brokers discussion board and in these articles:

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article, though she does have accounts at both merging brokerages.