by Kevin Indig for kevin-indig.com Attribution models are the most common way to quantify the returns on marketing investments, but not every company can use them successfully. Long sales cycles (+90 days) are the biggest enemy of attribution models, often to the detriment of channels like SEO that play an important role in early touches. Companies with long sales cycles often either sell B2B enterprise software (SaaS), high-priced products (e-commerce) or long-term commitments (consumer). The function of Marketing is to drive customers (if they can complete the buyer journey without talking to a person) or leads who connect with a…