Some phone users can’t commit to monthly plans. Instead these so-called prepaid users pay for buckets of minutes — effectively paying as they go.

Some subset of this group, AT&T’s market research indicates, won’t even commit to minutes — hence a new product offering. Starting Monday, AT&T will offer prepaid users the ability to pay $3 to make unlimited local and long-distance calls for one day. Pay $3 online in the morning, use the phone all day, then hang up and be done with it.

Mark Siegel, a spokesman for AT&T, said the theory behind the offering is that “prepaid callers are heterogeneous.”

Mr. Siegel said the company did not expect the plan’s potential customers to come from any particular age group or demographic. Rather, he said, “it’s for people who want to use the phone for a day without counting minutes.”

Obviously there has been growth in the use of prepaid calling plans. But something else may be at work here too. As network operators, like AT&T, get more sophisticated, they are able to introduce a growing number of billing plans and product offerings that slice and dice the way their networks are used.

In a conversation I had yesterday with Glenn Lurie, AT&T’s president of emerging devices, he mentioned the way business models and payment models are changing, perhaps even entering a phase of experimentation and chaos. Expect more offerings for consumers with widely varying habits and tastes, including commitment phobias.