The Costs of Bookmarking
This seems too expensive and I'd like to try and help, so I'm going to give you an idea of my hosting bill and why it's low and then suggest something for you:I pay around $3k per month. I own my own servers and lease a full rack and I serve roughly 1 billion page impressions per month. My bandwidth consumption is measured in Mbps rather than amount of data transferred because I get billed using 95th percentile billing. I average around 130 megabits per second of transfer - constantly, peaking at 150mbps I'm transferring roughly 40 terabytes of data per month. 95th percentile billing and owning your own servers is they key here.To give you an idea, for one month of your hosting bill you can buy 1, possibly 2 servers from Dell and put them in a half rack that will cost you around $800/month including power, secure access, bandwidth, etc. Those servers will last around 5 years with a possible drive replacement or two during that time for a few bucks.But I think you have another problem that's making things worse. With 15,000 active users you should be able to support them on one or two small Linode servers using round robin DNS. That's a relatively small user base and the number of requests per second can't be anything more than 10 per second? So I'm guessing something about your basic app architecture is off. It could be that you're not using Nginx to reverse proxy to Apache and you think you need more apache children/processes, and therefore more memory, than you actually do. You could have a DB that doesn't have indexes in the right places and so you're IO bound.I would suggest first looking at your app and seeing where the bottlenecks are in performance. Fix that first, then look at hosting.Questions:-How many servers do you currently have and give us a rough idea of config.-How many app requests per second do you get at peak?-What's your peak bandwidth throughput in Mbps?-On your servers, is lack of CPU or lack of disk throughput the bottleneck?-Have you had problems running out of memory that caused you to buy more servers? Which app ran out of memory?-Give us an idea of your server config. e.g. nginx -> Apache -> MySQL & Redis. Do the servers talk to each other and if so what do they do?