The following passage comes from chapter five, "The Voice of Society," of Sean Grass's Charles Dickens's "Our Mutual Friend": A Publishing History (2014), which Philip V. Allingham's reviewed. — George P. Landow.
t is not quite true . . . that Our Mutual Friend simply went dark after Dickens's death. Whatever the critics thought, he was far too popular for that. As even the selected list of Our Mutual Friend's editions in appendix 4 shows, publishers in England and America never stopped printing and selling this or any other novel by Dickens, instead issuing edition after edition of both individual titles and the collected works. Long after his death, owing to the combined effects of population growth, rising literacy rates, and a higher standard of living, Dickens continued to sell better with each passing year. Through the last decades of the nineteenth century and first decade of the twentieth, Dickens's titles almost single-handedly kept Chapman and Hall afloat, the publishers working the copyrights cleverly and continuously until the last one for Drood finally expired in 1913. In 1872 they launched the "Household Edition" in bound volumes, monthly parts, and penny numbers, and during 1873-76 they issued the more costly "Second Illustrated Library Edition." Then came the "De luxe Edition" of 1881, the 34-volume "Gadshill Edition" of 1897 — which Waugh calls "the first really complete edition of Dickens" because it includes his speeches and journalism — with introductions to the novels by Andrew Lang, the "Authentic Edition" of 1900, the "National Edition" of 1906, and the "Centenary Edition" of 1910. Nor were these all. In 1906 Chapman and Hall had 14 editions of Dickens's collected works in print, even though most of the novels — Our Mutual Friend and Edwin Drood excepted — were out of copyright and under production by other publishers, as we1l. When the copyright for Drood finally expired, Chapman and Hall flooded the market one final time with the economical 22-volume "Universal edition" of 1913, yet even this continuous reissue of Dickens's works was scarcely enough. During World War I, when most trade had slowed to a trickle, Dickens sales were still enormous, according to Waugh. The existing plates were used for one edition after another, and the profits were immediate and continuous." Scribner's sold them in America and Waverley helped to do so in England, and dealers in retail goods from tea to embroidered silk to the Encyclopedia Britannica attracted buyers by promising free sets of Dickens's works. Amid this relentless demand and despite continuous production, "the volumes could hardly be printed fast enough to keep pace" [Waugh, A Hundred Years of Publishing, Being the Story of Chapman & Hall, Ltd. (1930), p. 251]
Since the copyright for Dickens's works expired title by title from 1878 on, it is very hard to know for sure how many copies of his books really sold. But Chapman and Hall's figures, inasmuch as they remained the principal publishers, [133/134] at least give some indications. According to these, in the first dozen years after his death [i. e., 1870-1882] Dickens's books sold 4,239,000 copies, and Waugh told The Book Monthly editor James Milne in 1906 that for the prior six years Dickens had sold an average of 330,000 volumes annually — four times what he had sold in 1869. Moreover, Waugh reported, annual sales had been increasing at a rate of 30 per cent each year, so while the average figure for 1900-1905 was around 330,000, in 1906 sales were running more like half a million, not including sales in the United States. 
Grass, Sean. Charles Dickens’s Our Mutual Friend: A Publishing History. Burlington, VT, and Farnham, Surrey: Ashgate, 2014. [Review by Philip V. Allingham]
Last modified 21 May 2014