Because users have different operating systems, web browsers and computer hardware (including mobile devices and different screen sizes), online ads may appear to users differently from how the advertiser intended, or the ads may not display properly at all. A 2012 comScore study revealed that, on average, 31% of ads were not "in-view" when rendered, meaning they never had an opportunity to be seen. Rich media ads create even greater compatibility problems, as some developers may use competing (and exclusive) software to render the ads (see e.g. Comparison of HTML 5 and Flash).
InfusionSoft is a fully functional CRM and marketing solution created for small and medium size businesses. Comparing it to MailChimp or AWeber is like comparing a Lamborghini to a VW Golf. It provides highly advanced features for list segmentation, lead scoring and marketing automation. On top of all that, you can integrate all of these features with your optin form using Infusionsoft Tags + OptinMonster.