Important question about Google +

Hi!

i am hoping someone on here can shed some light on the following for me:

I am new to Google Plus. I heard that it can help boost SEO etc, so I signed up recently and have already added lots of posts, videos etc.

The problem however is:
I sell a digital product on a specially created sales page.

Google Plus lets you create an account as a person, an author. While you can add your website (ie in my case my sales page) to your profile and even mention it in your posts, Google Plus will do nothing to improve the SEO of a website or sales page you are trying to improve rankings for.

The profile may be found by people looking for me by name or even people that happen to come across my Google Plus profile by chance.

For example, if you are the author of a book 'How to make great Cheese cakes' and the book is sold on a website, then Google Plus merely promotes your name as an author.

But when someone googles the search terms 'how to make the great cheese cake' to find recipes, they may not find the website NOR the Google Plus profile.

So how does Google Plus improve SEO of web sites when it is just a profile or representation tool for people and not products?

It might help people find an author if they already know the name of the author and google it specifically, but it wouldn't work the other way around: if they google a search term like cheese cake, Google would (probably) not show the Google Plus profile of some author who wrote a book about cheese cakes, see what I mean?

And even if it did, the viewer would then only be guided to the sales page where the author is selling the book, if that viewer manages to see the website link on that Google Plus profile.

So how would G+ help rank a product website better?