Evauating and Marketing???

How do you evaluate a website. How do webmasters know when to get out or get in and really go for it with all the marketing mustard they can find.

I have a website www.bulletbobber.com and I sell a cool little fishing invention. Unfortunately I don't have the experience or the money for marketing and I am an idiot to internet marketing terminology. I am designer and want to find a partner to do marketing.
Do any full service marketing companies work for a % of sales?
Are there any willing to do what it takes to get a market going for something as unwired as a fishing invention.

I do have some market statistics.
The main was is that there are 250 million fishing floats sold each year in the US.