It is mainly done for the following reasons:

• To know what is wrong and be able to solve the errors within time
• To improve the efficiency and user experience which leads to business growth
• To be informed of any possible losses and bugs.

But have you thought what the intent of cross browser testing platforms like HeadSpin is. It is mainly of twofold:

1. The appearance of the webpage in various browsers- is it same, if one is better compared to other and so on.
2. The functionality as well as the working of it.