It doesn't seem that unreasonable to think that they have a continual need for additional developers. They're also not the only company that has a "We're Hirin

It doesn't seem that unreasonable to think that they have a continual need for additional developers. They're also not the only company that has a "We're Hiring" post in each of these threads which strikes me as a good thing--assuming the term of employment for new developers is longer than a month. :)