we're currently renting a full rack from AlphaRedHosting for just under a year and have been extremely happy with them. Our one year anniversary comes up March 31st and we plan to be here as long as they continue to perform as well as they have been, and providing the quality of support that they do.
Sometimes it seems like people change datacenters like they change socks!
I'd say that over 80% of our customers have been around for a year or more. Probably 40% have been around for 3 or more years. There's something to be said for choosing stability over price.