One of the reasons I wrote, “How to Build a Business and Sell It for Millions,” was that I foresaw a significant increase in the number of  cash-rich companies being purchased by larger companies.  If there is anything that validates my prediction, it’s the AT&T and T-Mobile merger.  AT&T just reached a definitive agreement to purchase T-Mobile in a cash-and-stock transaction valued at approximately $39 billion.  The deal is expected to take up to one year to close and will make AT&T the largest cellular carrier in the U.S.