Lots of the advice here is very general, but it's important to know what your product is before being able to supply advice.
Are there natural networks that would spread your product better than others? Tough to know without knowing what the product is.
As far as blogs, etc. That only works if your customers are reading blogs. Need to know what the product is.
Just because it's a "web product" doesn't make it b2b, so we need more info.
But I think the biggest thing I'm seeing from that you didn't write about what you've built is, to always be telling people about your product, always be learning.
I know it can come of as being a shill sometimes, and I've been accused of that, but if you have a mission of the way you want the world to work, so what if some people don't like that you told them about what you do.
Of course, the best way to do that is to make them curious, not just dump on them every chance you get.
You'll see a very common (though also somewhat annoying) process many people here on HN use, which I'm assuming is recommended to YC companies, it's very formulaic.
"Hey HN, I'm X and I have Y credentials. I had this problem, someone I know had this problem, have you ever had this, my co-founder Z , met when we were doing K (maybe not the drug), and we'd love to ..."
you get the point.