Book Reviews – how important are they?

I'm not sure that reviews are as essential as some people think as far as sales are concerned. Certainly, I am not influenced by a book having a few one and two star reviews as long as they have just as many four and five-star. What I find suspicious is when a book has fifty five-star reviews and nothing else. Neither am I influenced by a book not having more than a few reviews – I rarely leave a review myself – and I think a lot of readers feel the same. Too much of a chore to go through that process.
However, I have been turned down many times by BookBub and I can't think of any reason why this has happened unless it's because I don't have enough reviews for the book I've submitted. The only book they have accepted –Barbara's War – and goodness me, what a massive impact that had on my sales and income – had twenty reviews and now has double that. None of my other books have as many.
Therefore, I just paid for choosybookworm to put my book in their system. It was £100 to do this which is quite expensive, but fortunately I'm in the position to be able to speculate a little nowadays.
This is what they do:
you submit your book and they see if it's up to the standard they wish to promote.
they then, on the given day, send your book title etc to their thousands of subscribers and the subscribers decide if they want to have a free book in return for a fair/honest review.
they guarantee you will get 30+ reviews and keep putting your book out there until you have achieved that.
The reviewer has to put a disclaimer at the bottom of their review saying they received a free copy in return for a fair and honest review.
They sent me an initial list of ten names and already eight of them have responded and received the file.
My worry is that somehow this contravenes the rules on Amazon that reviews mustn't be paid for. Giving a reviewer a gift card to purchase the book contravenes the rules – I pointed this out to choosybookworm and they immediately changed my submission so that I was offering files rather than gift cards.
The reviewer isn't paid any money – I'm paying the facilitator. Does this count as a paid review or is it the same thing as sending an ARC?
I certainly wouldn't have invested so much money if I didn't think it might help me get a BookBub promotion for this book. I don't like to ask my readers at the end of the book to put up a review – I already have my free book  advert there, which a reader receives in return for signing to my subscribers list. I think that's more than enough.
It remains to be seen if this works and when I have 40+ reviews I actually get accepted for a BookBub promotion. It's always possible I've been turned down another reason.
What do you think? Is this breaking the rules or an excellent opportunity for writers to get those extra reviews?
Fenella J MIller