Fine Art America is the world's most powerful sales and marketing tool for photographers and visual artists.
Simply open an account, upload your images, set your prices for all our available products, and you're instantly in business! FAA provides you with an e-commerce website, fulfills your orders for you, and sends you your profits each month.
pinterest - i think i can get my name around, some people claim sales from that, but people just want to collect there.
instagram is for phones and bad filters, i honestly wouldn't consider it a social thing.
twitter helps, but you have to target friends well there.
google plus - i was kicked out for advertising, which they said was spamming. i never went back and i apparently am not missing anything.
facebook only works if they seek you out. while i can't say i have sales from there, lately it almost doubled my hits. if someone there likes your work, and they actually credit you with a link, you could get a lot of easy publicity there.
every place you can put your name the better, and with a name like McCoy - as in the The Real McCoy - you can get away with all kinds of advertising
If you are from a smaller city, don't forget to follow your local newspaper on Twitter. I was just asked by my local paper (they just found me on Twitter) if they could do a feature article of me for the weekend paper Bio, picture samples etc YAY.
Facebook - great if you put the time in
Twitter - fabulous if you put the time in
G+ - okay but very busy now. I have had commissions through that
Instagram - not really for sales but you can sell instagram prints on http://instaprints.com our sister site
Pinterest - some people saying they get sales but I have not seen that
As an artist, half of the work is marketing yourself.
Here are some good links to discussions in our forum and elsewhere about marketing your work