Smartphone adoption in the United States is growing at a pace so brisk that many analysts are being forced to eat their words (and previous projections) calling for a much slower transition from feature phones to smartphones.

According to the Mobile Marketing Association, all signs point to domestic smartphone penetration topping 80% within a decade.

At present, U.S. smartphone penetration stands at 51.8%.

Last month, the MMA released its newest report titled “How Big is the Mobile Marketing Opportunity.” Impressively, the report suggests that global ad spend could reach as much as $220 billion globally and $70 billion in the U.S. alone (that excludes mobile search).

As a direct result of this runaway growth, mobile marketing budgets among companies large and small will require augmentation to avoid missing the palpable opportunities that lie ahead.

“Our analysis indicates that the amount brands should spend on mobile has been grossly underestimated and that the industry is likely to be larger than currently predicted,” says Greg Stuart, the MMA’s CEO.