One of the reasons TFP has no paid advertising is that so many of the online stores sell products that are not really compatible with BBB (Pool chemicals, etc).
Someday, we may do some institutional adds that have no controversy (like Pentair, Hayward or a SWG manufacturer) but, for now, we do not accept paid advertising.
There are a lot of good online stores and, I'm sure, some not so good. Any information you get here is anecdotal in that someone may report a bad experience with XYZ but it turns out that someone else reports a good experience with the same company so you are not helped.
In a nutshell, it ends up being just a little bit of a **** shoot when you go online and the final judgement has to be whether you feel comfortable with them or not.