Although receiving an advertisement via a text message is less common in the U.S. than in some European countries, Americans are more likely to respond, according to a report released today by M:Metrics, a Seattle mobile measurement firm.

M:Metrics found that 17.2 percent of U.S. subscribers have received a text message ad in July, whereas in Europe as many as three out of four mobile subscribers reporting receiving one.

In the U.S., response rates were the highest, with 12 percent responding to the ads. The United Kingdom had the second highest response rates at 9.2 percent.

The big concern with sending ads via text message is that they will annoy customers, especially if they are sent without permission. Also, in the U.S., subscribers may be charged for the message if they do not have an unlimited texting plan.

M:Metrics found that across all geographies a majority, or 73 percent, of the ads are from the subscriber's mobile service provider; 17.5 percent of subscribers said they received an ad from a company that had permission to send it, and 21.1 percent said the advertisers did not have permission.

"Certainly the level of interaction is impressive compared to almost any advertising vehicle available today" said Evan Neufeld, a M:Metrics senior analyst. "It is undeniable that text-based mobile advertising is both a highly prevalent and an extremely effective medium for engaging customers."