Many, many people claim to be in love with their BlackBerry Messenger. I've seen a lot of posts from people saying that they would consider switching to a non-BB Device except that they can't stand to give up BBM.

So, what does BBM have over all the other IM apps out there? I use BBM and have not used any others. But, I think I've seen:

Live Messenger
Yahoo IM
Google Chat
AOL IM

and I'm guessing there are others.

So, what makes BBM a must-have where none of those others is an acceptable substitute?

For me, the fact the BBM uses PIN messaging and doesn't eat my my txt msg allocation.

I don't have (or need) another IM account. BBM, built into the BB OS, allows me to do IM to another BB user. Great when there is an infrastructure issue causing e-mail to be down or delayed.

And besides, who needs friends who don't have BlackBerrys?

And that's why my iPhone is up for sale.

In another thread, Midnightdraven said:

"There are no SMS IM programs.
AIM, Yahoo, GTalk, WLM all use data now."

So, if the other IMs don't use text messaging, then the advantage TonyEye cited isn't real (any more - I do believe it used to be the case).

So, if you only want to have one IM app on your phone, why pick BBM? Why not pick one that anybody can use, instead of limiting yourself to BB-only? I do have a *few* friends that don't have BB's, whom I might like to IM with, instead of using Text Messaging, like I do now.

Oh, and NJBlackBerry,

if the outage is because RIM is down, wouldn't that mean that BBM doesn't work either?

Of course, that really just highlights the fundamental weakness with all BBs. Everything goes through RIM servers. So, I think(?), if RIM is down, all the other IM apps would not work (on a BlackBerry), either.

Blackberry messenger is great if you have friends with blackberries.
Its always there, no signing in, works faster than most IM clients (WLM in particular is slow even on 3G).

I don't have friends with blackberries, I don't use it.
I have WLM, but I rarely use it, as my friends are also rarely on it, and im never away from a pc for long.

BBM is lightening-fast. I have found other IM programs so slow and laggy that I don't even bother with them. For my needs, either BBM does the trick or a couple of SMS messages. If I was going to have a longer conversation I would just (gasp!) make a voice call.

A few thoughts off the top of my head...

BBM conversations are encrypted as the traffic never leaves the BlackBerry infrastructure.

BBM offers delivery and read notifications.

BBM can be set up for internal use only on BES enabled handhelds. (Added security.)

BBM doesn't require an "account" to be set up on some public service somewhere which could possibly become compromised.

BBM can be audited by BES administrators which makes it more attractive than public IM clients in secured environments.

You can easily send pictures, files, audio, contact info, etc. over BBM.

BBM is pre-loaded on all BlackBerry devices.

BBM is "always on" and doesn't use as much battery power to run as third-party IM clients.

BBM has proven to be quite stable and is not the cause of memory leaks that plague other third-party apps.

You can easily change your BBM handle at will without your contacts needing to re-add you to their contact list.

BBM conversations and contact lists can be backed up locally to media card, or remotely via email. (With BBM 5)

For me, all the above + the simpicity and clean, uncomplicated user interface. I'm NOT talking about the 5.0 version though.

No - if our internal infrastructure or network has a problem, then BBM (or Pin to Pin) still works.

And, even with their outages, I'd bet that RIMs server uptime is 99.9%+ There are a lot of hours in a year.

I've never limited myself to one. I use BBM and Jivetalk.

Depends on the outage. Not all outages are equal. An SRP connection issue may not affect PIN messaging, for example.

Big reason, its built in. The user doesn't have to install anything. Trying to get a large group of people to install a program on their device just to chat is problematic. Some simply can't be bothered. But if its already there and they don't have to do anything, you will get more cooperation and participation. The security issue that has been brought up is a concern to only a small number of users. Most people's IMs are of trivial matters and most couldn't care less if anyone else saw them.