Internet advertising is synonymous with web advertising and online advertising. Technology advancement has enabled internet penetration into every part of our lives, and we are spending more time on internet. This creates high possibilities for an internet user to engage in online advertising. The first online advertisement that appeared on the web was in year 1994. The word online advertising is a marketing strategy that involves the use of internet medium to obtain web sites traffic, target and deliver marketing message to the right customers. Effectiveness of online advertisement study is based on the millennials. The Millennials are a cohorts born between 1981- 1997 and their ages are from 18 -37 at present. Millennials are also known as Generation Y or Gen Y (P.Bruntha, 2019). The digital prowess and market savvy of Millennials make them a difficult group for retailers to bracket. The present study centres on how this trillion dollar demographic of millennnials can be tapped by the marketers for the revenue generation.