I finally had a short amount of time to look at SMEStorage. It appears that you pay a flat fee to SMEStorage and they in turn use Amazon S3 for storage much like other sites. The difference here is that you only pay SMEStorage. At least that is how it seems. They charge $5.00 per month per 10 gigabytes. There is unlimited uploads and downloads of data.
The problem that I have with this model is that I prefer to pay what I use. I actually use very little, so my monthly Amazon S3 bill is very minimal. This could serve someone well who likes the idea of the S3 storage robustness, but the possibility of a large bill scares them away from other products.
It is great that we have another option for online storage.