There are hue and cries over reduction of effect of banner advertisements. But, that is not true. Still, advertisers show craving for media rich banners. Industry specialist Dr. Ralph F. Wilson, in a web article published at Web Marketing Today on March 31, 2009, observed that there might be some misconception regarding assessing banner ads. In brief, his observations are as follows:

Banner view or impression is the number of times it is viewed. For some consent management platform analytics, it is same as page hit or page view; however some do not consider a banner being viewed unless the viewer stays on the page till the banner is fully downloaded.

In most of the ads, a graphic is hyperlinked to the URL of the advertiser. In comparison to graphics or static graphic images, animated rich-media banners reportedly attract more viewers to the webpage of advertisers.

Internet Advertising Bureau (IAB) has suggested for standardization of banner sizes in their Ad Unit Guidelines. They have recommended sizes as follows:

a) 300x250 (Medium Rectangle),

b) 180x150 (Rectangle),

c) 728x90 (Leader board), and

d) 160x600 (Wide Skyscraper).

But, advertisers seldom following the guidelines.

The design should influences visitors to click a banner to reach the advertiser's website. The number of clicks determines the overall performance.
Cookies determine for the advertisers precisely which banner is converting into a sale. Therefore, cookies are the tools to judge the performance.
Run of Site (ROS) may be cheaper option of advertising with banners.
The author has also suggested some tools to measure performance in the same article. They are the followings:

Each banner can be traced up to the sale point with help of cookies. This is the most common practice in web ad industry.
Ad links can be tracked by analytics tools like Google Analytics by insertion of requisite coding.
Banners create brand awareness among internet surfers. Yet, the degree of awareness generation is hard to be quantified unless surveyed with questionnaires.
Low cost banner production, offering affiliate programs and developing highly enticing banner ad are some other means the author has suggested. Otherwise, according to the author, switching to text based pay per click advertisements will be the only resort.