This is a very weird test: hardly anyone knows that gmail actually has a tagline, and the tagline reads: Fast, searchable email with less spam
1) Fast, is an ambiguous term... and relative, so it needen't be tested
2) Searchable is a feature, its like a yes/no thing, either its there or it is not, but its there, and that settles the matter
3) Less spam: hmmm... now here we have a claim, the third part actually has a claim. You cannot take it for granted just because google says so... this needs to be verified.
Now lets see if gmail really has lesser spam than its compition. Now that hotmail is more or less out of the picture, I am extrapolating personal knowledge here, I dont have a hotmail account, the other corner has to have yahoo. There are various factors that need to be taken into account before a consensus can be reached. Namely:
1) How often the spam has been checked in both the accounts (never)
2) How often does spam get deleted in both the accounts (fortunately, never, keeping spam was apparently useful)
3) For how long spam has been allowed to get accumalated in an account (have the yahoo account for far longer than the gmail account, therefore more spam is to be expected in yahoo)
4) For how long the email id has been allowed to circulate amongst spammers (there, yahoo has even more reasons to have more spam)
5) For how long the spam stays in each account before getting automatically deleted (never? whoa... for some weird reason, this feature has been disabled in both the services OR the particular information for this factor is not available... ignoring the factor will not harm us much)
6) How many websites the address has gone to, and therefore in various so called anonymous mailing lists (I had purposely kept aside yahoo to recieve all such mail, and gmail for regular correspondance. All my newsletters, for example, get delivered to yahoo, and not gmail - this means that the probability of yahoo having more spam gets considerably spiked)
so, there are six factors, one ambiguous, two equalizers, and three for yahoo having more spam. This is ignoring any assumptions of technological superiority that google might or might not have.
The conclusion: yahoo is technologically superior than google, or there are other factors causing much, much, more spam in gmail than yahoo. Donno which is the stranger conclusion.