Gmail and Yahoo Mail are two of the most popular technologies on the web as the parent companies Google and Yahoo are often implementing lots of new goodies. But the most important aspect of the two services seems to be the storage capacity because the two providers are challenging each other with more and more attractive updates. It was all started a long time ago by Yahoo, the Sunnyvale super giant announcing that its Yahoo Mail will begin offering unlimited storage capacity for all the users. It was already known the fact that Gmail offers the largest storage size on the web so it was quite a hit for the Mountain View company.
Along with the infinite storage space, Yahoo also bundled Yahoo Messenger straight into Mail, a move inspired by Google Talk's interoperability with Gmail. At that time, Gmail didn't make any move but it replied in a funny way: the Google technology will be soon offering unlimited capacity plus one, just to be over the Sunnyvale rivals from Yahoo. We all thought it was only a joke, even Yahoo did.
Time passed by and Yahoo implemented the unlimited storage size along with the new Yahoo Mail. Google made a reticent move and decided to allow the interested consumers to buy additional space for small prices. For example, you can buy 6GB for $20,00 per year as well as 250GB for $500,00 per year.
Even if Google allowed consumers to buy additional space, Yahoo was the one offering unlimited storage size which makes its technology more attractive for the consumers. However, a few days ago new rumors were quickly spread on the web: Google prepares a new capacity update for all the users. The speculations were not confirmed until today when the Google officials confirmed they made a modification in the counter which will increase Gmail's storage size faster. But still no sign of unlimited + 1 capacity.
Personally, I don't see the storage size as a main aspect when it comes to choosing an email technology. Think that whatever your storage capacity is, you're not allowed to send files over a couple of MB so it's useful only if you receive tons of messages every day.