The 3G connection from my iPhone is my primary modem at home. With an unlimited plan and pretty good signal, it works pretty well for what I need.

The funny thing is that when I need to download something bigger than 20mb from the App Store I have to use iTunes, which is using the tethered 3G anyway.

It's very annoying to be out, find out about an interesting app, and then have to remember to download it at home on WiFi because it's over 20MB (inevitably, I don't remember).

Ironically, my wifi at home is just serving up a 3G signal anyway so it's all going over the same network.

You'd think that it would mark it as "to be downloaded later" and then when you were back home either sync it from iTunes or prompt you to download over WiFi.

I've wanted this feature for awhile, too.

One workaround for this is to remind yourself about apps of interest by taking a screenshot (pressing top button and home button at the same time) and looking over your photos later when you sync with iTunes. Unfortunately, this workaround applies more to app users than app developers.

I have a friend that works on the iOS platform - and his first client wanted a digital brochure for a well known luxury sedan. They paid well over six figures for the application and because of all the assets in it, it was over 600MB.

I wonder how many downloads that prevented. What is Apple's policy with putting a small app on the store that just downloads the rest of the content once run?

I believe that's how the Ikea app and at least one Wikipedia-based app (sorry, can't remember the name) work. Small app download, followed by a larger content download.

Nobody's gonna let it download 600 MB more over that same 3G connection on first launch. People would just be even more disappointed.

It depends on the content. IIRC, you can't download executable code – JSON is fine.

I know many game developers that download assets (spritemaps, textures, etc) over http. In fact, it was one of the bullet points in Apple's Optimizing game development on iOS talk this past WWDC.

"the size increase can be large when the binary has a lot of contagious zeros in it."

I think what they mean is that if your decompressed binary has long chunks of zeroes which compress really well, when it is encrypted (thanks DRM) those long series of zeroes get changed to non-reapeating data and are no longer easily compressible.

Usually: sizeof(compress(data)) <= sizeof(compress(encrypt(data)))

Why not first compressing then encrypting?

I suppose you might conceivably actually call them "contagious" zeroes rather than contiguous zeroes in that case.

You can't really compress encrypted data. If it's encrypted it looks more or less like random data. So any encryption is very likely to result in a (minor) size increase, when compared to the original.

That's what I was trying to say in my comment.

Normally app sizes increase by 0.6mb after submission, but with one of our iPad apps, the file size actually decreased after Apple did their magic.

Is there a practical reason for the limit? I tend to switch to tethering over Verizon 3G for large downloads as it is faster than my ADSL connection. I don't have an iPhone, but I can't imagine the benefit of a potentially slower connection to download something.

Prevent overloading radio networks and avoid nuking data quotas, which are still extremely common on cell phone networks?

sms and data in the us (now that unlimited is out... Hold to that contact of yours) are more expensive than operating hubble and transmitting said data for the consumer.

So saying that usage is culprit to network congestion is pretty simplistic. Only reason is lack of investment.

I always assumed it was a concession to AT&T when the data plans were unlimited.

The operators told them so.

Why do you think every heavy app had this limit? Skype over 3g? Forget. Itunes is just another victim.

Why do you think only months after att cut out the option of a unlimited data plan everyone is announcing data heavy stuff? Android even has voip now.

Expect that limit to go away next ios update.