If you are an established site, please share with us how many backlinks you got before you saw steady traffic coming to your forum/site. Thanks
There are too many variables to answer this question. What you want to know is how many backlinks you need to rank and even that can't be answered except on a case by case basis. Even the number of backlinks isn't really a valid question because the quality of backlinks is much more important. You need to know how competitive the keywords are you are trying to rank for and that the more competition there is the more work you will need to do. I just read a post on another forum about a guy that spent 13 months building links to get on page one. He is in 'making money online' which is super competitive so 13 months is reasonable. Yahoo Site Explorer can give you an idea of what your competition has done though I think Site Explorer only shows about 20% of the backlinks so you will probably want to multiply what it shows by 5x.
You are making the question more complex then it should be, and its really simple. If you have 5000k visitors per month, then how many backlinks do you have...Its fairly simple... I am not saying these stats will work for everyone... Its just interesting coversation to how much traffic you are getting vs the number of backlinks you have...will it work for someone else, i doubt it...but its just fun info...
I hate to say it, but if you're metering your traffic off of the number of backlinks you have, then I think you're going about it the wrong way. The reason I'm saying this is because the quality of your backlinks directly affects how many visitors you'll get, first and foremost. One backlink from, say, the front page of Yahoo, can provide ten-fold the traffic 1,000 blog comment backlinks would. The other reason I say this is that backlinks are typically only used in SEO, which then results in an increase int he number of visitors you receive from a search engine. Though, there are a few types of links that are outside the realm of SEO (in my opinion, anyway), like Yahoo Answers.
If you build backlinks to your inner pages as you go along, you should be able to get a steady stream of traffic right from the beginning. Otherwise it can take a good year or two to get any kind of authority for your site.
Backlinks are importartant, but even tho I think you have to build a good number of them, thy dont have to be your main motivation on building you site/reputation. I think that backlinks are the natural process on the evolution of your website/bussines. Once people see that you deliver quality content, and also Search engines start to see that, your backliks will grow without you doing nothing about it. That happened to one of my websites some months ago. I worked on backlinks for about 3 months, but...I had quality content, good presentation, and good info, so once people comes in and sees that, backlinks are going to get even better.
It is all depends the way you build your links. I personally don't purchase any links and build my own by using free online sites. Take advantage of web 2.0 sites and don't spend too much time by submitting to online directories. Also, don't waste your money to purchase links. Link to your inner pages. In time you will see the benefits. Also, when you are building links, try to create link wheel to improve the value of your backlinks.
There's no magic number of backlinks you have to have before a site becomes successful. It depends on your niche, the competition, and dozens of other factors.