Sales of existing homes showed another gain in May, benefiting from favorable affordability conditions and a first-time buyer tax credit, according to the National Association of Realtors®. May's increase was the first back-to-back monthly gain since September 2005. Existing-home sales – including single-family, townhomes, condominiums and co-ops – rose 2.4 percent to a seasonally adjusted annual rate 1 of 4.77 million units in May from a downwardly revised level of 4.66 million units in April, but remained 3.6 percent below the 4.95 million-unit pace in May 2008.