I've been using Getsocial since June 2016 for my games (Fancy Cats and Fancy Dogs). So far so good, I've been really satisfied with the tool. The support is also very friendly and effective (hey Viral). The pricing, IMO, could be a bit "better", for example: users from different country tiers will have different "value", for a certain month I may have store featuring with hundred thousands of new users but mostly from 3rd tier countries, so perhaps you should consider "ratios" (e.g. 0.6 for users in 2nd-tier countries, 0.3 for users in 3rs-tier countries).