It is very possible that you have a situation where you have a big dataset coming in and only want to add the rows from it to your spreadsheet that are new. For this, my manager Eugenia came up with a very nifty and creative combination of the append feature and the =FILTER() formula. The way this works is that you will need three tabs.
Tab1 - The tab where only new entries need to be added.
Tab2 - The filter tab that works between tab1 and tab3. From here a Sheetgo append connection takes the new data and appends it to tab1.
Tab3 - The big dataset.
Another thing you need is a column with a unique identifier. This can be an email address, shipping address or a entry id as long as it’s 100% unique for each row. For instructions on how to set this up, I’ve created this example https://docs.google.com/spreadsheets/d/16ijl6_N5i2FzQfbYv_sbJ14xRgn_fAcE/copy
Please note that it’s only possible to add new entries at the bottom of the list, not the top.