VWO is a good tool to start making A/B tests or Multivariate tests in a website when you don´t have too much money to invest on this type of activity. There is even a cheaper option, like Google Website Optimizer, but still VWO I think it is easier to use and provides better features, so it is worth the small cost.
An introductory video on VWO:
Here I provide some information, coming from VWO guys, where it is compared VWO tool against Test&Target and Google Website Optimizer.
| Visual Website Optimizer | Omniture Test & Target | Google Website Optimizer | |
| Core Features: | |||
| A/B testing ? |  | | |
| Multivariate testing ? | | | |
| Visual WYSIWYG editor ? | | |  |
| Easy tag-less integration ? | | | |
| Multiple conversion goals ? | | | |
| Realtime reports ? | | | |
| Heatmaps & clickmaps ? | | | |
| Advanced Features: | |||
| Visitor segmentation & targeting ? | | | |
| Revenue Tracking ? | | | |
| Integration with Google Analytics ? | | | |
| Cross-domain tracking ? | | | |
| Wordpress, Joomla plugins ? | | | |
| Automatic test monitoring & optimization ? | | | |
| HTML, CSS and JQuery based tests ? | | | |
| API to fetch test results ? | | | |
| Collaboration Features: | |||
| Multiple permission-based logins ? | | | |
| Client or project sub-accounts ? | | | |
| Support | From product developers | Support team | Through forums |
| Pricing | Starts $49 per month | Annual contract of $10,000+ | Free |
