1. Free hosting
2. Layout customization
3. Integration with desktop publishing tools
All of the above are achieved by Blogger. There are other aspects that Blogger is have advantages:
1. Bearing the name of Google
2. Simple setup, particularly good for novice
3. Reiterate that. FREE
However according to the Blog software comparison chart, Blogger is actually the platform with least features! The good thing is it is having the most important features enough to draw in new bloggers, yet to achieve sustainable growth I would suggest the following to be added at a higher prioirty:
1) Category / Tagging
To sort the entries in terms of its relevant topic, each topic can generate its own XML feed.
2) RSS feed
RSS is afterall an open standard. Though Blogger is upholding atom feeds, it does no harm to offer one more option to the users.
3) Trackbacks
It is particularly important as author tends to link up his essays right after he has composed it. It is pretty inconvenient to login to haloscan, record the perm-link and trackback link... It simply takes too much time.
We can't ask for that much though, Blogger is a free service afterall...