We have been made aware by Betfair that heavy use of Practice Mode may place your Betfair account at risk of suspension.
Normal use should not cause any problems but continued and ongoing use of practice mode will cause your account to fit into what Betfair call a 'commercial use profile'. I.e. lots of data being pulled from them without any betting activity.
This is from Betfair: -
It’s important to make it clear to customers that it is not acceptable to read Betfair data on an ongoing basis.
The reason for this is that an account that behaves in this way represents a commercial usage profile and we would the look to close an account under our terms and conditions.
Any customer who wishes to read Betfair data for analysis and testing purposes should use the Historical Data services offered. Short term strategy/software testing with a view to betting/constructing a betting strategy is acceptable but to avoid account closure through our commercial profiling customers should look to access historical data for any longer term analysis.
If you feel you have been unfairly targetted we suggest you contact Betfair directly on the following forum to appeal. We are unable to do this on your behalf: -