Azure websites?

Also:

-It is very difficult to find a provider with always-on promise, and the closer to 100% reliability, the more the hosting price will go up. In practice, 99.5% guaranteed availability would probably be enough for your purposes, as your application does not seem like mission critical :)

-Dedicated IP is not necessary for neither SSL nor SEO. SSL certificates are typically bound to the domain name, not the IP. SEO doesn't particularly rely on static IPs either, again, it is the domain name that matters.

-Unlimited space and bandwidth are available if you are willing to pay for them. If your data volume is huge, this won't be cheap.

-Cloud hosting providers can charge you per actual resource use, so you can start small and when you do get revenue, you will be able to afford scaling up incrementally. For example, Azure provides very cheap basic hosting, but you can seamlessly scale it up when you need more capacity and can spend more.

Yea, if you can live with flat (but extremely flexible) database, Azure provides very cost-effective and scalable table storage.

Azure can also handle SQL Server and DocumentDB (new JSON-based SQL-queryable storage), but they do cost a bit more. Nothing to break the bank, though, if you get the basic tiers. And if you don't mind spending some tens of dollars per month, you could of course get a virtual machine instance and host about any database engine there -- Linux- and Solaris-based engines included.

I may be biased in my opinions as I have somewhat close ties with Microsoft, but if I had to make an objective choice as to which cloud provider to use, I'd choose Azure any day.

The basic tier SQL Azure database is about 4 dollars per month, and gives you 2GB of capacity. The next tier, S0, gives 250GB for about 12 dollars per month.

The basic website plan is free, but you can't bind custom domains (and therefore SSL) to the free tier. The next tier, "shared", is about 10 dollars per month, and does allow custom domains but is still on a shared machine (as in your own VM instance, but on a shared physical machine).

As your traffic grows, you should have a revenue plan (such as advertising) that would cover the scale-up costs.

For a starting website, the prices for Azure are very reasonable, considering that you don't have the obligation to insert Microsoft's advertisements on your site, even on the free plan. The only thing that tells the visitors of the free plan site that it is hosted in Azure, is the domain name that always ends with "azurewebsites.net" (for example, mysite.azurewebsites.net). You can use your custom domain with the cheapest paid plan ($10).

Also, as we said earlier, if you can store your data in a flat table storage, Azure table storage would be the cheapest solution. It is very powerful and scalable, but does not support SQL specifically, nor does it have built-in relational capabilities. The table storage is priced per actual usage, and scales seamlessly when your data grows. Table storage also has very high performance as it is optimized for the Azure storage architecture.

A new database option, DocumentDB, is also now generally available; it stores records as JSON blobs, and you can perform SQL queries against the data even though no schema is required for the data itself. DocumentDB is also cheaper than the SQL Server or SQL Azure.