1. Approximately once a month, that frequency will double if I am working on a project.
2. Customer service is the biggest one for me on or offline, second is selection, followed closely by price (the more I can get from one source the better as to save on shipping even if prices are slightly higher).
3. Generally I will purchase from the same store if they meet my criteria above (good service, selection, price, etc) if they do I have no reason to go elsewhere. I also like to shop locally (Ontario) so I frequently use the same sources.
Durate et vosmet rebus servate secundis.