If your site has an interesting title and description, then you'll receive some traffic from being in positions 8-10 but it will be barely anything compared to the traffic you would receive in positions 1-3. Percentage-wise, it's impossible to say... it could be 5% or 1%. It all depends on the user - are they getting what they want from the top results? If they are, then why will they leave those sites and come to yours?

My advice is to keep building backlinks so you can get into that top 3. Like I said, you should receive some traffic from the 8-10 positions, but it's not going to be much.

Page 1 of Google is quite overrated I think. You are probably looking at 2% of clicks for one of those positions. The top 3 probably take up 85% of clicks depending on whose research you base that on.

Like Liam said keep building links and doing your SEO. I always and aim for top 3 and see a dramatic increase in traffic for a keyword when one of my sites gets there.

i'm never happy with ranking anything other than #1. We are in SEO to rank number #1 so why settle for anything else.

Good news for you is that what you are doing now to rank is obviously working for you. All you need to do it keep on truck'n with what you are doing and get it set in your mind that its number #1 or nothing... Don't stop until you get it even when you feel it may never happen.

One magical google algo change and you may find yourself with a flood of traffic and sales from your site moving to number #1 over night.

For anything, I also give myself a reasonable time frame for my goal. For newer sites I give myself at least one year to get a #1 ranking. You have to build domain authority before really ranking for more competitive terms and this takes time (around 6 months with google)