eBay is the top brand name on the net, according to calculations by net monitoring company Envisional.
Brand awareness online has increased as more people shop on the net
It scored the highest in terms of how positively it is perceived on the net, compared to McDonald's which had the most negative perception online.
Microsoft was the most prominent company name in the index, but it was the sixth most negatively perceived.
The DEX index was calculated using a scoring system which works out popularity across the net.
"The internet is fast approaching television in terms of influence on consumer behaviour and therefore big brands cannot afford to neglect the issue of how their brand is perceived on the web," said Ben Coppin, chief of Envisional.
MOST PROMINENT BRANDS
1 - Microsoft
2 - Google
3 - Yahoo
4 - Sony
5 - HP
"For a brand holder, gaining any kind of useful information about a brand or company's standing on the internet - particularly in comparison with competitors - is tremendously difficult."
Response to critics
eBay has recently had an advertising campaign on UK TV, and has seen its profits boosted too.
The success of the PayPal online payment service has helped to take sales over the $1bn mark, eBay said. It is relying on emerging markets, like China, to add more users to its auction service.
McDonald's has featured in the news over the last year as the result of the Supersize Me film, as well as the conclusion of the McLibel case, the longest running legal case in English history.
The fast food giant has responded to criticisms a result by introducing healthier menu options, including salads.
LEAST POPULAR BRANDS
1 - McDonald's
2 - Coca-Cola
3 - Wal-Mart
4 - Nestle
5 - Unilever
It also put adverts in five newspapers saying its food should be eaten as "part of a balanced diet".
Microsoft's Windows operating system is used on the vast majority of personal computers globally, and has recently heavily publicised its Service Pack security update, which affected all of its customers using Windows XP.
It also issues monthly bulletins which make people aware of potential flaws or security holes which have been discovered.
But a lot more people are also becoming aware of brand names online in general and talk about them online, in blogs, for instance.
Market analysts, Verdict, recently found the internet was the fastest growing retail sector last year, attracting one in four shoppers.
Envisional looked at 100 companies from the FTSE-100.
The DEX metric is worked out based on the number of web pages, news sites and bulletin boards which feature each brand, as well as the prominence of the company name in each occurrence.
MOST POPULAR BRANDS
1 - eBay
2 - HP
3 - Dell
4 - Mini
5 - UPS
The popularity of each company is then judged by combining "sentiment" measurements, which scores each brand name according to negative and positive references in the context in which the brand is discussed.
Google came out top as the most popular online brand in a survey by web magazine, Brandchannel.com, in 2003.
It came in second as the most prominent brand in Envisional index, but did not make the top 20 in terms of most negatively or positively thought of.
McDonald's was unavailable for comment at the time of writing.