The Painkiller“
hey there ...
(Alexander &Hill, 2006) It’s widely understood that it is far less costly to keep existing customer than it is to win new ones (p. 1), attracting new customers requires high costs on marketing campaigns that would include: advertising and promotion ..
”
Hi,
I was taught how to reference in the Harvard system. Are you trying to use the same system? If the answer is yes, you need to put the source after your sentence, not before. Also, I was taught that the number of the page has to be written only if you're quoting a sentence word by word (I mean, within quotation marks) from your reference book, while it is omitted when you paraphrase the source, by using your own words.
So, if you're rewording Alexander & Hill's work and they state that a company should try and keep their customers, you'd write:
It is widely understood that it is far less costly to keep existing customer than it is to win new ones (Alexander & Hill, 2006). Attracting new customers requires high costs on marketing campaigns that would include, for instance, advertising and promotion.
”
or, if they affirm that when a firm wants to attract new customers, they have to pay extra cost for advertisements etc.:
It is widely understood that it is far less costly to keep existing customer than it is to win new ones. Attracting new customers requires high costs on marketing campaigns that would include, for instance, advertising and promotion (Alexander & Hill, 2006).
”
However, if you're copying at least four words consecutively (that was the rule in my Uni!

) from their book, you need the number of the page:
It is widely understood that it is "far less costly to keep existing customer than it is to win new ones" (Alexander & Hill, 2006, p. 1). Attracting new customers requires high costs on marketing campaigns that would include, for instance, advertising and promotion.
”
(if, for instance
"far ... ones" is an excerpt from the book you're quoting)
A couple of comments:
- It is better not to use contraction in an academic paper.
- Avoid ellipsis (.. after
promotion)
-
Attracting new ... is a new sentence. Either you start a new sentence or you make use of connectors if you want to keep it joined with the first one
This website has a pretty good and comprehensive guide to the Harvard System of Referencing. They also cover reference materials from the internet (section 3.4).