Byron includes once piece of “product placement” in Canto 1 of Don Juan; a mocking encomium to Rowland’s “Incomparable” Macassar oil whose superior qualities alone could match those of Donna Inez.
“In virtues nothing earthly could surpass her,
Save thine ‘incomparable oil’, Macassar.”
The joke worked so well because the Alexander Rowlands, father and son, were incessant puff-merchants for their own products — which included Essence of Tyre (for dyeing grey or red hair a dark auburn color) and Alsana Extract (for “eradicating disorders of the teeth”) — frequently the form of verse advertisements in the Gazettes. The following indicative extract is taken from Rowlands Jnr.‘s A Practical and Philosophical Treatise on the Human Hair, published in 1814
In antient times a flow of Hair,
Reclining on the shoulders bare,
Was view’d a mark of beauty’s pride,
A fact which n’er can be deny’d
Proof that “advertising works” may, in fact, be the lasting legacy of The Incomparable Macassar Oil, for it became a wildly fasionable treatment for baldness — or maybe wig-hair — among the trivial, newly-wealthy, fasionable (middle) classes of Regency England, as John Rowlindson’s cartoon suggests.
Curiously, Byron’s backhanded “compliment” to the product was not the end of the joke. The Rowlands returned the “compliment” in an advertisement among the back-papers of the Tenth (monthly) installment of Charles Dickens’ The Pickwick Papers published on a freezing, snowbound last-day of December of 1836 (London roads were impassable, snow lay at a depth of 5–15 feet in places with drifts up to 20ft).
The full-page advertisement, reproduced below, purported to be “missing verses” from Don Juan, further detailing Inez’ use of Rowlands’ products for the hair and teeth in a hacker’s version of ottava rima but, naturally, without the satire that enlivened Byron’s reference to the products.
You can find a full account of the influence the advertisement may have had on an episode in the twelfth instalment of The Pickwick Papers here