Ajax,
take a hard look at the ingredients on the package. I might be wrong, but i am pretty sure that the bio-spot and harts stuff use pyrethrins as the active ingredient. pyrethrins just dont cut it anymore. the flea and tick populations have built up resistance over the years. Frontline will do the trick 98% of the time.
Another alternative (cheaper) would be to use Ivomec once a month. I have alot of clients that use oral ivomec once a month for heartworms that say it does the trick for fleas and ticks too. I dont have anything but their word to go on, but that is what they say. I know that Ivomec will kill fleas and ticks, I am just unsure about how long it lasts in their system after dosing it. Just make sure your dog is heartworm negative before you use it!!!