It's good that your product can provide results, but so can many others. That alone is not enough to help you stand out, it's the requirement to even get started.
There are arguably two main factors that will make or break your WSO success:
1. Who's backing you (big name affiliates and testimonials can give you credibility and get attention to your offer)
2. An irresistible offer with strong copywriting (sales copy)
One of the key things necessary in order to have a successful WSO launch is having a bunch of affiliates on board. This alone can product hundreds of sales for you. Naturally, you should have a quality product and good copy - - but the main thing is having the affiliates backing your launch.
As mentioned, affiliates and copy are key. Firstly, the affiliates:
Make sure you're offering 100% on the front end and have an OTO or upsell (at least 1) in place - otherwise a lot of affiliates won't touch it. If you can afford a contest, that's a good way to kick start that as well. Post in as many JV groups about your launch details as possible. Secondly, the copy:
Your system works which is great. You'll want to include screen shot proof of this. For example, a shot of commissions that came into your account within a certain time period of that 1 blog post.
Testimonials - right on the sales page - are huge. By all means give out a review copy or 2 and get some well known people testing your product, in exchange for a testimonial that you can put right on the sales copy.
Guarantee - completely optional but a proven conversion booster. Your call.
Obviously there are volumes written on how to attract affiliates and how to write converting copy, but those are a few key tips that should point you in the right direction. Hope it helps!