A study by AMI-Partners says that companies with one to 999 employees will spend $18 billion on wireless services this year. The report, Small and Medium Business: The Next Growth Engine For Wireless Service Providers, says that Verizon Wireless, Cingular, Sprint and T-Mobile are actively going after this market. Some examples: Sprint and Cingular have created SMB-specific rate plans and contract options and Verizon Wireless has established a vertical-specific SMB sales team. The report says that 76 percent of small businesses and 88 percent of medium-size businesses use mobile services.