It’s not that search engines haven’t been trying. Just last week, Google (NSDQ: GOOG) introduced an analytics dashboard that gives small businesses a better read on their local search traffic. But “the quick emergence of the multibillion-dollar paid-search industry has spawned unrealistic expectations among local businesses eager to turn the Web into a cash register,” the Borrell analysts write. Many small businesses don’t see return on investments from their ad spend, while others think that they are being ripped off by resellers. It’s unclear though just how much cash is being left behind. Borrell Associates, for instance, still expects search advertising spending by local businesses to reach $5.3 billion in 2013, up from $4.1 billion last year. But for search engines—and even sites like MySpace and MSN—that see local advertising as a still largely untapped market, the findings have to be cause for concern, considering that they imply that many businesses that might initially purchase ads won’t be in for the long haul.