if your targeting that market why not offer it so payed members are hosted there and everyone else uses bandwidth from American servers. with just 10k uniques a day you could get away with a cheap p4 with a good chunk of bandwidth for about $140 a month. which is far more sustainable in the long run. you also need to be very very careful putting adsence ads displayed next to uploaded images as it's against there tos. i have been having trouble with adsense just on my main landing page with no outgoing links to the content thats been uploaded. how many clicks where you getting on adsence per day ? the ads on adbrite that seem to decently well on my site are money making, dating, internet tv etc. so you may want to try filtering your ads to get more money. if you activate full page ads you may get up to around $1 a day on adbrite with your current ads, it also takes awhile to build up ad inventory on adbrite, sometimes months if not longer. your traffic is also fairly low, so your not going to get advertisers directly purchasing ads from you until you reach at least 5k uniques a day. with only 13k unique a month you would be much beater of on a vps, you could actualy stay on that vps untill you reach near 5k or more a day depending on your image hosting software.
Yes i was considering premium members to have the servers in poland and others in Germany. The AdSense is deactivated, i excluded it form my allowed sites and I put there adbreite or something