How a review impacts my chances of going to a place depends a great deal on the answers to a variety of questions.
Does the reviewer write good reviews?
Do they do a lot of them for various sorts of places?
Do they ever like anything?
Do they only ever complain?
Have they ever reviewed a place I've been, and do I agree with their assessment?
Do they seem to have an axe to grind and appear spiteful instead of helpful?
Do they offer specific examples of things they liked/disliked about the place so I can make up my own mind how I feel about those things?
Is there a lot of controversy over the place? Do some people love it while others hate it? What, specifically, do they like/hate?
Some people hate to feel neglected by staff in restaurants, I prefer they don't hover. So when someone says something about being neglected by staff, unless they follow it up with specifics like "we waited two hours for our entrees" I tend to discount it a little bit (not entirely).
A recent example for me was when we went to Washington DC two weeks ago, I had Oyamel down as a place to visit. I'd been watching the reviews of this place on the DC chowhound boards, and there was a flurry of "they oversalt their food" posts a few weeks before we were to leave. There were also many posts saying the food was great, though a little over priced, and several posts saying that it was really good for the prices. Well I -really- wanted to go because the menu looked fantastic (goat tacos, what's NOT to love about that?). So I decided that I didn't mind even if it was salty because I -like- salty food anyway. We took a bit of a chance on it, and I'm VERY glad we did. It was outstanding. Nothing was oversalted, everything was perfectly seasoned and wonderful and the service was great, as well. They were warm, and welcoming, and helpful. I can't say enough good about it.
So I took their reviews with... heh... a grain of salt.
So no, a single bad review is not likely to keep me from going to a place unless it is =very= detailed and really about things I agree are awful.