Took me more than 2 years to get 200 paying customers for my Web App

I'm kind of conflicted on this. Yes, it is hard to get ten people to pay money, in that you have to have a mostly-functioning product, a website which markets it, and some way to charge their credit cards. But this is not really that hard.

BCC 1.02 ("Like 1.00, but with less crash bugs and the brand new ability to print to non-default printers") got to ten customers in six weeks from 1.0's launch, entirely on the strength of organic search marketing on two pieces of content. That was when I was young and stupid. Y'all can do better.

I think software (let's scope it to B2C software for the moment) is like lemonade stands. You know how you get ten customers with a lemonade stand? Your price? Doesn't really matter. Your stand's design? Doesn't really matter. Your taste? Doesn't really matter. Your location? Probably matters for getting hundreds or thousands of customers, but for 10, pretty much any street will do. The key hurdle you have to get over is charging money for lemonade. I am worried that people think it is really really hard to run a successful business, and that stops them from ever charging for lemonade.

I meant "pays your rent" quite literally. As in, taking the biggest of your financial worries away and leaving you only needing to deal with the spending money part. So you still can't live on your income, but you can coast along for an entire year on $10k savings.

Up to that point, $10k in the bank meant you'd better start scrambling to pick up a contract in the next couple months before you run out of money.

The cost of customer acquisition can be very high for a bootstrapped startup to afford. For example, Constant Contact (for $20/mo subscription) spends $375 as cost to acquire one customer. Spending a major chunk of $2k to acquire just a few paying customers may or may not be a viable strategy (depends on numerous variables, of course).

Source of data: http://investor.constantcontact.com/annuals.cfm

This is simply not true. You need to be found but that doesn't mean spending money on advertising. I hit this mark without spending a dime on advertising. A large amount of my traffic comes from owning the most important keywords for my niche. The rest from WOM and blog posts from others about my product (reviews, interviews, CSS galleries, etc.)

Those costs will be largely fixed as the site grows. I may experiment with other advertising to see what if anything converts, but I think the site would do fine without it.