Doing some search engine optimization work in your website to draw more visitors alone is not going to boost up your online revenue. You should do tasks that convert the visitors to your website into customers. There lies the success in online marketing. Not all SEO company will do conversion marketing and conversion management. You have to find out whether the SEO company that is working on your website for search engine optimization can do the conversion marketing too. Otherwise you can outsource the conversion marketing work to another company. If you can find an SEO company that can do SEO as well as conversion marketing then that would be the killer combination for your success online.
A few right tweaks here and there might attract your visitors to your website often. You should have features that visitors can rely upon. For example an SSL encryption for the transactions might give the confidence to the users to conduct any transaction without the fear of losing their confidential data to hackers. Live interactions with the service staff through chat features integrated in your website will enable them to clear their doubts if any immediately this would be added advantage in conversion marketing.