A mobile based service (like eko) which aims at reaching out to a billion such 'mobile' Indians today has to contend with another truth - illiteracy. If this Times of India article is right, our illiterate population equals the entire population of the USA!
At Tinfo Mobile, this fact had driven me to design an application series titled TeachMe Akshara which would run on even the basic mobile handsets supporting Java (which were then being given out by Reliance Communications for prices as low as 500 bucks). The purpose of this app was to teach its users the basic alphabets of Indian languages. This news article on Digit magazine talked about that app. Unfortunately, that app never got formally deployed and I've moved on.
What was amazing about Eko was that the great folks here had put in a great deal of research and thought into this problem and had come out with a mobile interface that could be used by even the most basic mobile user, because the solution involved nothing more than dialing!
Resonating with the Eko team's findings, is this research paper published a few years ago by the Nokia Research Center authored by Jan Chipchase - a pioneer in mobile usage research. Here is a link to the research paper titled: Understanding Non-Literacy as a Barrier to Mobile Phone Communication
The following excerpt is particularly interesting:
The simple answer is that non-literate mobile phone users can call, but cannot message or use the address book. The subtleties are more interesting than this.
Two basic tasks were easy for almost all our participants to complete: turning on the phone and answering an incoming call. Beyond this, there were various degrees of success. Dialing a local phone number is relatively easy, but problems can occur when there are variations such as dialing a national or international number, or using IP telephone prefixes. ...