Witht a quarter of US homes now cell-only, research association AAPOR recently updated its guidelines for cellphone surveys, warning that researchers risk unrepresentative results when studying the full population if they don’t include cellphones in their samples.

Cellphone dialling is added at no additional charge to the client, said Ipsos.

Chris Deeney, senior vice president of Ipsos Public Affairs’ omnibus division, said: “The market research industry is a rapidly changing business. Adapting to changes in the population is a continuous challenge for us… We were among the first to offer Spanish completes as part of our standard telephone omnibus so we are taking a similar approach with the addition of cellphone dialling as wireless usage continues to grow.”