Philatelists/frustrated novelists take note! Perhaps you simply need another medium to find success. After all, one of the most popular novels of the twentieth century, Jack Kerouac's On The Road was written on a long single roll of printing paper.
If you've got any airmail lettersheets left over, perhaps that's just the inspiration you'll need to become the next Charles Dickens. During WWII author James Leasor wrote his first novel on Airgraphs, the sheets that were photographically reduced and sent home to the UK from soldiers and sailors overseas. A devoted mother at home typed up the the missives for him and helped to create a true epistolary novel.
Something of a precursor to Ian Flemming, Leasor specialized in novels of political intrigue and espionage. One of his most popular novels was Passport to Oblivion (1964). His Airgraph novel -- his first -- was Not Such a Bad Day (1946), for which, the Daily Telegraph reported in his 2007 obit, he received the princely sum of £50.