Patrick writes a good, data-driven, post about the impact of the 'introduce yourself' post.
You can break down the numbers below:
I think he's misinterpreting the data. It's hard to believe that introducing yourself years ago would make the difference between moving from 1000 to 2000 posts.
From the data above, the members who did introduce themselves have a bigger sample size after 200 posts. This isn't very useful for assessing it's long-term impact.
What we want to know is the % drop-off rate from one post category to the next?
The key question is will it help members to get to 50 posts in the first place? See the data below:
This shows what % of those that were in the previous category made enough posts to reach the next category.
Here you can see that there is a big difference between those that introduce themselves to get from 1 to 50 posts (30.6% vs- 9.4%), but the introducer affect wears off relatively quickly after that.
After >200 posts, introducing yourself has no significant impact. I suspect, your psychological sense of community plays a bigger role.
To simplify, this data shows one of two things. It either shows that if you introduce yourself in the community, you're about 22.2% more likely to reach the 50 post mark. Or it shows that the people most likely to reach the 50 post mark, also tend to introduce themselves.
If we wanted to know for sure, we would need a controlled trial with a random sample of prospective members. Half would be able to see and participate in the introduce yourself thread, half would not.
Since we don't have that data, I recommend the these videos from Josh Elman and The Student Room's Jack Wallington.