I faced this question in my interview. I said that I
found this field interesting for me and I am good in finding
bugs. The more bugs I find the more I get satisfied.

hai,

   Now a days in IT industry,companies are giving more
importance to quality.Providing the quality only any product
or company can survive in the market.Now a days website are
playing major role in the world like ecommerce
apps,webportals,service providing for free like(Yahoo,rediff
in mails).U need to maintain the quality in the apps.So that
Quality engineer is required for getting the quality in the
apps.
generally devlopers also test the apps in +ve way only.Bust
Tester can test in both the ways(+ve&-ve).OK

r u satisfy with this answer.If not am sorry.

I feel proud choosing testing field. Finds faults in others
work which will help in the customer satisfaction and bug
free product. Testers will be the key responsible for
quality product which gives the good reputation to your
company, project and you. it is a challenging job and I like
to take up challenges to give the value additions to the
product quality and customer satisfaction.