How to get users enganged and active in a new website?

Me and my team are working on an online project where people can give away unwanted stuff and get stuff they are looking for.

The problem is that from my experience people tend to get engaged in things that already have big numbers.

How do you get people posting their content/stuff at the very beginning of the website?

What incentives can you use to get the first 500 to 1000 users?

The most vocal and insightful person I know on community building is Alexis Ohanian, the cofounder of Reddit. Here's a great article he published the other day on this exact topic.

I've outlined some points I've heard him make before on how he and Steve Huffman built up Reddit:

1. They populate the site with useful content from fake users so that when someone knew arrived, they would think there was already a community.
2. He extensively used scwag (stickers, shirts, etc) to build offline connections. Physically mailing stuff is hard, so if you do you'll create a fan for life.
3. There product was just as useful to 20 people as it was for 20,000 people. Try to make it so that your site is still useful for a small number.

And some of my own thoughts

1. Start with a small, niche and branch out from there. If you're strapped by geo-location, then start only in one city.
2. Go out to events and talk about your product
3. Make sure it is something you would actively use and couldn't live without.

Another way is to simply fake it. Although this is a very fine line from a moral perspective you can keep on the 'safe' side of it.

If you simulate a number of accounts and transactions between those accounts it can make your site look more active than it really is. Using the technique described in the previous answer (the Focus Group model) you are more likely to have people use the site because it appears to have more activity when they go to investigate. Apparently this technique has been used by some major sites when they first launched (I did read an article about Digg or Reddit using the same technique when they launched - I can't find it via Google right now though so I have to ask you to trust my memory).

You should probably mark all simulated accounts and entries as such (perhaps a special glyph next to the user or entry that has been generated internally rather than by a member). The effect is more about perception than reality - even though the (potential) new user knows that what they are seeing has been generated and is not 'real' a site showing pages of activity is more appealing than one with empty pages waiting to be filled.

Here is a few things I would personally do to be able to justify this method to myself:

1/ You should notify all existing users that you are about to populate the site with simulated data. Do NOT use any previous user names or transactions as samples.

2/ All simulated transactions should be realistic and not skewed to provide a different view of potential gains (ie: no transactions swapping an X-Box 360 for a footstool).

3/ Include 'worst-case' scenarios (ie: an offer of an X-Box 360 for a footstool being rejected because you are not likely to receive the X-Box).

4/ Positive and negative reviews of the simulated users.

5/ Any contact (messages, friend requests, etc) to simulated users being responded to with a message that clearly indicates that the user is simulated and not real.

6/ All simulated accounts, transactions and entries expire after a fixed time period (say - 3 months, if you don't have a 'critical mass' of users by then you probably need to re-investigate your model) and are no longer visible.

6/ Don't charge for services until all simulated transactions have been removed from the site.

You probably want to generate this sort of data anyway to test your site layout and API (if you have one) rather than just depend on 'Lorem Ipsum' for everything. It makes sense to re-use that effort to help attract people to your site as well. The golden rule is 'harm no-one' - don't use fake data to attract paying users, don't skew your data to imply things that aren't true and make it possible for users to see what transactions are fake (simulated, testing, etc) compared to what are true.

Best of luck,

ShaneG