I stumbled on a thread at Nairaland yesterday, where the OP shared
the NCC (Nigeria Communications Commission) response to her query on why
Nigeria network providers can't make other data plans to be as cheap as
BIS (Blackberry Internet Subscription). I'm sure you will agree with me
that the issue of expensive data plans especially for Android
smartphones has been generating a lot of comments online lately.
According to the thread, RIM, the manufacturer of BlackBerry, utilizes a special compression algorithm to serve users of Blackberry handsets who have subscribed for BIS. Whenever such a BIS subscriber surfs the internet and opens a webpage, a request is sent via the BB's browser requesting for the page to be downloaded to the phone. This request is channeled to RIM’s gateway in Canada, which fetches the webpage, compresses it and sends the compressed data back to the BlackBerry phone as a download.
On an Android smartphone, the request to open a webpage by subscribers is sent to the gateway of the network operator which then processes the information and sends back the page to the Android phone as a download (the data is not compressed - thereby requiring more bandwidth).
The amount of bandwidth uploaded is identical between both Blackberry and Android phones, the difference lies in the fact that most of what subscribers do on their phones is to download content which varies on both. BlackBerry is indirectly subsidizing bandwidth by compressing the content downloaded by subscribers.
In effect, an internet subscriber using an Android smartphone to open a webpage may be downloading 100KB of data, while a subscriber using a Blackberry opening the very same webpage would be downloading 25KB due to the compression of data by RIM.
Bandwidth in Nigeria is an expensive resource, because most data is transferred wirelessly. This is the reason why the NCC is promoting wired infrastructure around the country through such projects as WIN (Wire Nigeria) as well promoting a Broadband roadmap for the country which will greatly reduce the cost of bandwidth thereby reducing the cost of browsing the internet on smartphones.
I hope you now understand why BIS might continue to be cheaper than other data bundles.