I am pleasantly surprised that Google Drive has increased her free storage from 5GB to 15GB. Maybe it is due to competition – Other cloud storage providers are offering bigger storage than 5GB. I personally won’t leave Google Drive even she did not increase the capacity.
So, no need to delete files when your storage is getting near to 5GB, but it is still a good practice to keep useless files cleaned all the time, no matter how big storage you have.
我才发现 Google Drive 和 Gmail、Picasa 的总容量合并以后限额 15GB。总容量没有实质提高，但方便很多。比如我 Gmail 占用不多，就可以让 Google Drive 多用一些。