The broker basically resets the positions and provides either a credit or debit for the interest rate differential between the two currencies in the pairs being held. The trade carries on and the trader doesn't need to deliver or settle the transaction. When the trade is closed the trader realizes their profit or loss based on their original transaction price and the price they closed the trade at. The rollover credits or debits could either add to this gain or detract from it.
Rob Booker is a forex seminar entertainer, a forex "systems" marketer and he is not a successful trader. I can say this from plenty of personal experience: I attended two of his seminars, co-taught another one with him in Canada, and am mentioned in his book. Once Rob held a contest to see who could submit the most profitable system. A guy wrote an elaborate description of a "winning system" and submitted it, knowing full well that it was a system that was a guaranteed loser. Rob awarded him first place, lol, and never tested the system! Rob makes nearly all of his (big) money from selling systems-of-the-month (stuff you can easily find online.) He has not been seen on FF since professional trader Phil McGrew (look him up here--his posts are gold) made him his "buddy" and would speak the truth whenever Rob would post. Stay far away from this clown.
Most brokers also provide leverage. Many brokers in the U.S. provide leverage up to 50:1. Let's assume our trader uses 10:1 leverage on this transaction. If using 10:1 leverage the trader is not required to have $5,000 in their account, even though they are trading $5,000 worth of currency. They only need $500. As long as they have $500 and 10:1 leverage they can trade $5,000 worth of currency. If they utilize 20:1 leverage, they only need $250 in their account (because $250 * 20 = $5,000).
Apart from the podcasts, Rob has also brought on board a few writers who publish their supposed success stories. For example, I came across one post from a guy who claimed that he was ranking among the top 5 technical currency analysts yet he was not making profits during the early stages of his trading career. Then as time went by, he learned how to do it right. All of a sudden, this guy started making $1,000 a day by trading what he had learned.
For traders—especially those with limited funds—day trading or swing trading in small amounts is easier in the forex market than other markets. For those with longer-term horizons and larger funds, long-term fundamentals-based trading or a carry trade can be profitable. A focus on understanding the macroeconomic fundamentals driving currency values and experience with technical analysis will help new forex traders to become more profitable. (For related reading, see "Benefits & Risks of Trading Forex with Bitcoin")