The book industry is a cut-throat one, nowadays. In the UK Waterstones have a monopoly in the High Street and can therefore dictate trends in publishing. Meanwhile, mega internet businesses such as Amazon exercise enormous control over the pricing. In order to sell their books to these outlets publishers are obliged to offer huge discounts. And, of course, this means that the person who did all the hard work - the writer - gets an increasingly small share. 10% doesn't sound too bad if you are talking about £12, but 10% of £3 is not a living wage.
One way for an author to earn a little bit more from her book is buy acting as an agent. A Family Outing in the Atlantic is available from various online stores, including Amazon. If you use this link to travel directly from this site to Amazon Jill will earn roughly 6% on anything and everything that you buy, including her books. The 6% is NOT added to your bill; you won't pay any more than usual.