I'm going to assume by cloud, you mean a cloud VPS hosting provider. If you want some cheap, bare bone VPS's, DigitalOcean has worked for us.<p>+ After shopping around, $5/month for a 512MB ram server is about as cheap as you can get.<p>+ Simple to spin up a VPS (as opposed to Azure, which requires you to jump through hoops if you just want a Linux server).<p>+ Great API for managing VPS's- simple, solid and intuitive (although AWS/EC2, while more complex due to additional features, is also very intuitive).<p>+ Great customer support - you can browse to creating a new VPS or opening a new ticket from the same page. Easy support and quick responses.<p>(+/-)? VERY basic VPS hosting. They provide the minimum amount of distance between yourself and your server. You need to be command line friendly. A good example of the difference between DigitalOcean and AWS/EC2 is that you will need to manage your own firewall (with EC2 they do it for you via security groups). For me the reduced distance is a plus, but if you are inquiring about technology supported this may be a minus for you.<p>(+/-)? Lack of PaaS features: this is IaaS, you will be given a VPS somewhere on the interwebs, and you will need to be able to manage it. If you need support for MongoDB, Rails or the like this may not be for you. You will need to install/configure the entire stack.<p>- Downtime! We migrated our entire infrastructure from EC2 to DigitalOcean around October(ish?) 2013. In that time period there have been 3 significant data centre outages (one lasting an hour or two). OTOH they are very transparent about issues that have occurred and have given detailed post-mortems.
If you are using rails or Sinatra I am a fan of cloud66. It manages deployment and you can back it with a half dozen different cloud providers. If you have load balancing enabled you can hook up to multiple servers from multiple providers.