A page title serves to identify your page, and thereby very briefly summarize it. It is not supposed to be a full description.

Here's a bad title:

Farquart's Tubular Emporium — Get all your tubular stuff here at low prices, and have lots of fun at the same time.

A title is supposed to suggest a name for the page. You don't say:

Hold on! We could get all those parts easily from Farquart's Tubular Emporium — Get all your tubular stuff here at low prices, and have lots of fun at the same time. who offer free delivery.

…unless you've been paid to! You just say:

Hold on! We could get all those parts easily from Farquart's Tubular Emporium who offer free delivery.

So the title should just be:

Farquart's Tubular Emporium

That's sufficent identification for those who are already familiar with the site. Meanwhile, for those who don't recognise the title, you could place that catchy slogan in the page's <meta> description:

<meta name="Description"
  content="Get all your tubular stuff here at low prices,
           and have lots of fun at the same time.">

Now you've separately marked up what it's called and what it's for.