Larry Chase's Web Digest for Marketers, which turned 10 this year, has issued predictions on the likely trends in online marketing for the next 10 years, NetImperative reports. WDFM points, inter alia, to podcasting, which will come to include B2B content downloads; pay-per-call advertising; multimedia blogs; reverb marketing; vertical search engines; the resolution of the spam problem; and email as an important marketing channel.