mkwawa
-from was i read on case studies abroad, security is not an issue, there already many web application that are used as transaction systems abroad like paypal and amazon the system enable any one carry out transaction, they are secure and reliable.
-as for internet speed, it is up you the user, if you have fast internet that fine, if it is slow it is up to you.
-also web apps came with advantange of not having to install application softwares for client users and as you all know this makes them ideal to be used in cloud computing