Petitions & Polls
Here's the problem...
Those of us that have created applications *unashamed plug* Petitions & Polls (Search for me - Dan Offer ;)) for example, that create GENUINE useful additional functionality. I've spent quite a lot of time and money developing this - and wish I hadn't bothered. Facebook have been horrific in changing things, and limiting the scope of growth for those of us that have just released their applications.
Only have one way really to promote their applications: invites/profile listings
The problem is that many applications go out of their way to SPAM other users, using the "social proof" of the user...to generate additional users. The only way to generate profit is (1) A large user base AND (2) Active users.
Many current applications, lack the ability to CUSTOMISE and have inaccurate user notification procedures.
The shere volume of "invite application spam" DEVALUES other applications that add genuine funtionality and are genuinely useful to users of Facebook.
The general perception of Facebook applications by users has become "Oh no, not another useless Facebook application" - this has made it a problem for enterprising developers like myself.
Furthermore, Facebook has had a tendancy to "steal ideas" and functionality of plugins (i.e. User Wall) of applications that people have spent time and money on creating their "plugin business" and integrated it within their portal. Rendering other peoples plugins useless.
I was initially optimistic, with this application - opportunity, for both users and developers...now, my faith is wavering.
*Shameless plug* my application:
Petitions and Polls
http://warwick.facebook.com/apps/application.php?api_key=152b3bfda61e655bc5f6c46505416379