With the new postal regulations of December 24th, 1901, the words Post Card replaced Private Mailing Card on the backs of privately made cards. Government issued cards would retain the title of Postal though the public would soon use both names interchangeably. The previous issued size restrictions were also relaxed. As the images gracing the front of postcards grew larger only a small blank border tab, usually along the bottom or side, remained to write a message. With increasing quality cards were now beginning to be purchased largely for their pictorial value. The higher quality of cards created greater demand bringing ever more publishers into the business. Many of the names that would rise to importance in postcard publishing were in business by 1903.
Use the link below for a more compleate history of this period.