In the article I quoted, Victoria wrote, "According to a 2004 article in Publishers Weekly, only 83 of more than 18,000 iUniverse titles published during that year sold at least 500 copies."
If you have a look at the link she provided you'll find this information about sales figures for iUniverse books in 2004:
18,108: Total number of titles publishedSo 18,108 different titles were published in 2004 and a total of 792,814 books were printed, which gives a mean average of 43.8 copies printed per title. And as iUniverse relies on print-on-demand technology, and only prints books in direct response to orders, “printed” here is the same as “sold”.
14: Number of titles sold through B&N's bricks-and-mortar stores (nationally)
83: Number of titles that sold at least 500 copies
792,814: Number of copies printed
32,445: Number of copies sold of iUniverse's top seller, If I Knew Then by Amy Fisher
If you take away the 32,445 copies that Amy Fisher's book sold and then do the numbers again, that average number of copies sold per title goes down to 41.9.
If you then consider that 83 of iUniverse’s books sold at least 500 copies, and take those 83 books and their sales out of the equation (for simplicity I’ve assumed that they sold bang-on 500 copies each but several will have sold more, and so reduce this average further), the remainder of the books published—that’s a whole 18,025 titles, or 99.5% of all books that iUniverse publishes—sold an average of 39.9 copies each.
Let’s assume that those books were priced at £10 each (which is a reasonable-ish price for a paperback right now). I don’t know what rate of royalties they’d have earned from iUniverse (anyone?), so can’t make a direct comparison here: but let’s assume that the writers had not self-published their books and had instead been published by a mainstream publisher, with a contract which specified a reasonable-to-generous royalty of 12% of cover price. On that deal they’d make £1.20 per copy sold: so on sales of 40 copies they’d earn a total of just £48 per book published.
I’d like to find out how many of the titles concerned sold under twenty copies: this would at least filter out a lot of the people who used iUniverse to produce books just for friends and family and had no intention of ever seeking sales for them (which is how I’ve used Lulu in the past). Because if I could take those books off the total it would push the averages up a little bit and give us a better idea of the average sales levels that iUniverse authors were achieving when these numbers were collated—but the numbers would still have a long way to go before they equalled the sales figures of the least successful books from a mainstream publisher.