Your Avenue will increase in rank dependant on the points you gain in reward for guiding the visitors to their desired store. The increase in rank will also bring you rewards, such as eventually being able to personalise the Join Avenue name to your own desire.
To reach Lv. 100, you will need +3000 Popularity points and once at Lv. 71, you will receive a Stardust every level, a Rare Candy every 10 levels and a Comet Shard at Lv. 100.
For each shop individually, I couldn't find the amount of points you need, to reach Rank 10 however I have been self initiative and thought if I divide 3000 by the amount of shops (7), that will give me the amount of points needed to get each of them to Rank 10 as I guess this adds together to get the overall Popularity Points for Join Avenue. Therefore, 429 points is needed for each shop to get to Rank 10. (I may be wrong but this is my best bet, as nothing is said on the web about each individual shop only for Join Avenue as an overall.)
Source: PkmnNet
Hope I helped :)
