Lack of marketing strategy and execution integration seems to be a common challenge to many companies face when there are “silos” within the marketing channels. Inevitably, your customers will end up seeing different creative, different offers, and different price points.
Your integration efforts would probably needs to start at your “List” level. For best integration, you’ll want to make sure all channels are working of a shared List/customer database. Depending on who your customer is, you would then build an integrated segmentation strategy (who gets what channel as well as what offer/incentive, etc.). You will also want to make sure to pay attention to touch points and marketing calendar — you don’t want customers getting a flood of communication from different channels, so keep things on the same marketing calendar and decide how much is appropriate for each segment/channel.
To determine the best strategy, you could run some tests — select a control group and then do some split or A/B testing (DM vs Email, or DM & Email, etc.).
Most experts agree that the evidence supports sending mail first and following with email a week after a timed in-home mail date. You can find some case studies with more information on this at the DMA (Direct Marketing Assocation) website: www.the-dma.org.
I would certainly advice on a cohesive messaging and offer value. We tend to do DM first (strong branding effect, as its in-hand and tangible) followed by a reminder email that reinforces the offer (one week later). I have also seen it to be effective to send “reminder” emails on regular intervals during the promotion period (this will depend on how long your promotion is to last).
Finally, all channels are usually tied to a custom-built micro site that pulls the promo together. Usually, the micro site should be created to match your corporate or product brand. I also like to use tracking links and unique URLs on DM vs Email to be able to measure which creative caused the customer to take action or respond, as well as to test various email creative.