Cannes, France--Jupiter Communications Inc. said Monday that global spending on Internet advertising will grow from $4.3 billion in 1999 to $28 billion by 2005. The San Francisco-based research firm said the market holds huge opportunity for corporate branding efforts but that the medium is throttled by regional media-buying budgets, a hesitation to embrace the new medium and insufficient understanding of the Internet's global reach. Jupiter, which made its announcement at its Global Online Advertising Forum in Cannes, France, found that $3.5 billion in 1999 Internet advertising was focused on the U.S. The second- and the third-largest markets--Western Europe ($400 million) and Asia ($200 million), respectively--lagged far behind. B-to-b advertising dollars were not broken out in the report.