Yeah, but...
1. They both end in "mon" (as in, "Hey, mon, what's up?")
2. Both games deal with collecting various annoying creatures
3. They both take place in some sort of alternate universe where said creatures are commonplace
4. The creatures in both games will grow into some bigger, badder form
5. Both series had one or more crappy movies based on it
6. Both Digimon and Pokemon have some sort of "main" creature used in all their marketing (Pokemon - Pikachu, Digimon - That little annoying dinosaur thing)
7. They both have a trading-card game